Methods and apparatuses for solvent-assisted polymer direct printing in air

ABSTRACT

A polymer three-dimensional (3D) printing methodology is disclosed for freeform fabrication of polymeric structures under ambient conditions without the use of printed support structures, without use of a support bath, and the like. The build material can be dissolved in a suitable solvent for 3D printing. The polymer solution can be printed (e.g., continuously printed using a moving dispensing nozzle) in air without the use of supports (e.g., without the use of a support bath, a concurrently printed support posts, or the like) while a nebulized coagulation agent is dispersed alongside the printed polymer solution to at least partially coagulate the polymer solution and form an intermediate article. The self-supporting intermediate article may then be immersed in a post-printing coagulation solution to remove some or all of the remaining solvent, causing the build material to fully solidify to form a finished article from the intermediate article.

GOVERNMENT SUPPORT STATEMENT

This invention was made with government support under 1762941 awarded bythe National Science Foundation. The government has certain rights inthe invention.

TECHNICAL FIELD

Embodiments described herein relate generally to additive manufacturing,and more particularly to freeform additive manufacturing of polymericmaterials.

BACKGROUND

Additive manufacturing, also referred to as three-dimensional (3D)printing, encompasses a range of technologies used to fabricate parts byadding material to build up the part rather than by subtracting unwantedmaterial away from a bulk starting workpiece. Generally, 3D printingforms parts by depositing and/or solidifying build materiallayer-by-layer in computer-controlled patterns generated from a digitalpart model; each layer forms a thin slice of the complete part and thelayers are integrated to form a tangible part based on the digitalmodel. In fused deposition modeling (FDM), a widely implemented type of3D printing, a thermoplastic build material in the form of a filament ismelted and extruded from a hot tip to generate 3D parts layer-by-layerin a controlled spatial pattern; as in other 3D printing processes, thepart is first generated as a computer model, then transformed intocommands for a 3D printer. FDM can be used for fabricating prototypesand products from rigid thermoplastic polymer materials, such aspoly(lactic acid) (PLA) and acrylonitrile-butadiene-styrene (ABS).However, a heating unit and process are required to melt the polymer andmake it printable through the tip.

As FDM printing technology continues to mature, there is a demand formore versatile approaches which are compatible with a wider range ofpolymeric build materials to fabricate more complex prototypes andend-use parts with a broad range of properties and features under milderconditions.

SUMMARY

A polymer three-dimensional (3D) printing method and associatedapparatus are disclosed for fabrication of 3D printed structures andarticles. In some embodiments, the fabrication may be freeformfabrication. In some embodiments, the 3D printed structures and articlesmay be formed from a build material, such as a polymeric material withthe assistance of a solvent or a polymer/solvent solution.

In some embodiments, 3D printed structures and articles may befabricated under ambient conditions and/or without the use of printedsupport structures which would need to be removed after 3D printing inorder to achieve the finished structure or article. In some embodiments,a build material can be dissolved in a suitable solvent or solventsolution (e.g., solvent/non-solvent mixture) such that the resultingsolution is a suitable ink for 3D printing. In some embodiments, thebuild material can comprise one or more polymers or a polymer solution.In some embodiments, the ink, comprising the build material, can bedisposed within a printing volume or onto a printing platform withoutthe use of supports or other structures being previously, concurrently,or subsequently printed to support the build material while the buildmaterial solidifies. In some embodiments, freeform printing can becarried out at ambient temperature and pressure. In some embodiments,just previous to, concurrent with, or just following the disposition ofink into the printing volume or onto the printing platform, a volume ofa coagulation agent, such as a coagulant, a non-solvent, variationsthereof, or combinations thereof, can be disposed, such as by an aerosolsprayer or other suitable dispensing mechanism, to a volume directlyadjacent the disposed ink. Without wishing to be bound by any particulartheory, the coagulation agent can cause partial, substantially complete,or complete coagulation, solidification, polymerization, phaseinversion, cross-linking, crystallization, calcification, concretion,setting, stiffening, hardening, amalgamation, strengthening, gelation,congealing, thickening, densification, annealing, shaping, forming,clotting, variations thereof, combinations thereof, or the like. Assuch, a first volume of ink can be printed, e.g., by a nozzle or thelike, in a freeform manner directly into air and partially or fullysolidified by disposing a first volume of the coagulation agentsufficiently close by the printed ink, the nozzle can move a distance,in a particular direction, from the previous printing location and printa second volume of ink, e.g., adjacent the first volume of ink (nowpartially or fully solidified), dispose a second volume of thecoagulation agent to partially or fully solidify the second volume ofink, and continue along a predetermined path through the printing volumeor across the printing platform in order to completely print anintermediate or finished article without being required to melt thebuild material, without using support structures, and/or without using asupport bath or the like to maintain the structure of the printedarticle prior to completion of printing of the article. In someembodiments, an intermediate article may be one in which some or all ofthe article is only partially solidified or for which further processingis helpful or required to achieve the finished article.

In some embodiments, if an intermediate article is formed for which someor all of the liquid build material only partially coagulates, heat, achemical reactant, electromagnetic radiation, and/or the like may beused to fully solidify or otherwise process the intermediate article toform the finished article.

In some embodiments, a method for three-dimensional printing of aprinted article can comprise forming a liquid build material, the liquidbuild material comprising a polymeric material in a solvent; disposingthe liquid build material into a volume of air; and spraying a nebulizedcoagulation agent within a predetermined distance of the disposed liquidbuild material to at least partially coagulate the liquid buildmaterial, thereby forming the article. In some embodiments, spraying thenebulized coagulation agent within the predetermined distance of thedisposed liquid build material is done within a predetermined timefollowing the disposing the liquid build material into the volume ofair. In some embodiments, spraying the nebulized coagulation agentwithin the predetermined distance of the disposed liquid build materialwithin the predetermined time following the disposing the liquid buildmaterial into the volume of air only partially coagulates the liquidbuild material. As such, in some embodiments, the method can furthercomprise, in an instance in which spraying the nebulized coagulationagent within the predetermined distance of the disposed liquid buildmaterial only partially coagulates the liquid build material, exposingthe intermediate article to a post-printing coagulation solution tofully solidify the intermediate article, forming the finished article.In some embodiments, exposing the intermediate article to thepost-printing coagulation solution comprises submerging the intermediatearticle in a bath of the post-printing coagulation solution. In someembodiments, the method further comprises dissolving the polymericmaterial in the solvent to form the liquid build material. In someembodiments, at least one of the forming, the disposing, the spraying,or the exposing is carried out by an apparatus comprising one or morereservoirs configured to contain a supply of the liquid build material,a nozzle, and a computing device. In some embodiments, the nozzle isconfigured and dimensioned to move along a predetermined path within thevolume of air to dispose a volume of the liquid build material. In someembodiments, the predetermined path is determined by the computingdevice based upon an input design file comprising a design of thefinished article. In some embodiments, the apparatus is configured tocommunicate the liquid build material from the reservoir, through thenozzle, and into the volume of air. In some embodiments, theintermediate article is formed free of printed support structures.

In some embodiments, the method can further comprise, optionally,dissolving a polymeric material in a solvent to form the build material(e.g., “the liquid build material,” “the ink,” or “the polymericsolution”). In some embodiments, the build material can comprise anysuitable polymeric material such as a thermoplastic. In someembodiments, a polymeric material can be dissolved or dispersed in anysuitable solvent. In some embodiments, such a solvent can comprisedimethyl sulfoxide (DMSO), and/or the like. In some embodiments, to formthe build material, the polymeric material can be dissolved in thesolvent partially or fully, at about room temperature (about 20° C. toabout 25° C.), or at an elevated temperature, while being stirred,shaken, agitated, bombarded with electromagnetic radiation and/orultrasonic sound waves, or the like. In some embodiments, one or moresolvents can be chosen that are capable of breaking down the buildmaterial without causing molecular degradation or a reduction in thedegree of polymerization (DP). Conventional additive manufacturing and3D printing techniques for polymeric materials typically requiresmelting the polymeric material at least partially if not fully tofacilitate the communication and build-up of the article using thepolymeric material. These conventional additive manufacturing and 3Dprinting techniques for polymeric materials can require high heat, whichcan make the process costly, dangerous, time-consuming, and limiting interms of the reusability of printing materials. By contrast, the roomtemperature process according to some embodiments described hereinrequires no heating of the printing materials, no thermal deteriorationof the polymers, and can eliminate the process step from conventionaladditive manufacturing and 3D printing methods of heating and/or meltingthe polymeric material.

According to another embodiment, a method can be provided for 3Dprinting an article that comprises: disposing a first volume of a liquidbuild material onto a substrate; within a predetermined time followingdisposing the first volume of the liquid build material onto thesubstrate, spraying a first volume of a nebulized coagulation agentwithin a predetermined distance of the disposed first volume of theliquid build material to at least partially coagulate the first volumeof the first volume of the liquid build material; disposing a secondvolume of the liquid build material onto at least a portion of the atleast partially coagulated first volume of the liquid build material;and within the predetermined time following disposing the second volumeof the liquid build material onto at least the portion of the at leastpartially coagulated first volume of the liquid build material, sprayinga second volume of the nebulized coagulation agent within thepredetermined distance of the disposed second volume of the liquid buildmaterial to at least partially coagulate the second volume of the liquidbuild material. In some embodiments, in an instance in which sprayingthe first volume and the second volume of the nebulized coagulationagent within the predetermined distance of the disposed first and secondvolumes of the liquid build material only partially coagulates the firstand second volumes of the liquid build material, the method can furthercomprise: exposing the article to a post-printing coagulation solutionto fully solidify the article. In some embodiments, exposing the articleto the post-printing coagulation solution comprises submerging thearticle in a bath of the post-printing coagulation solution. In someembodiments, the liquid build material comprises at least one polymericmaterial and at least one solvent. In some embodiments, the method canbe carried out by an apparatus comprising one or more reservoirsconfigured to contain a supply of the liquid build material, a nozzle,and a computing device. In some embodiments, the nozzle is configuredand dimensioned to move along a predetermined path within the volume ofair to dispose a volume of the liquid build material. In someembodiments, the predetermined path is determined by the computingdevice based upon an input design file comprising a design of thefinished article. In some embodiments, the apparatus can be configuredto communicate the liquid build material from the reservoir, through thenozzle, and into the volume of air.

As such, according to another embodiment, an apparatus can be providedfor 3D printing a finished article. In some embodiments, the apparatuscan comprise: a printing space comprising an air-filled inner volume anda printing substrate; a reservoir configured to contain a supply of aliquid build material; a nozzle coupled to the reservoir and configuredto dispose a volume of the liquid build material into the air-filledinner volume of the printing space; a nebulizer configured to nebulize acoagulation agent and disperse the nebulized coagulation agent within apredetermined distance of the disposed volume of liquid build materialto at least partially coagulate the disposed volume of liquid buildmaterial; and a computing device configured to control movement of thenozzle and the disposing of the volume of the liquid build material intothe air-filled inner volume of the printing space. In some embodiments,the nebulized coagulation agent may only partially coagulate thedisposed volume of liquid build material to form an intermediatearticle. As such, in some embodiments, the apparatus can furthercomprise, optionally, a solidification bath comprising a coagulationsolution, the solidification bath configured to, in an instance in whichthe nebulized coagulation agent only partially coagulates the disposedvolume of liquid build material, receive the intermediate article andcause, via the coagulation fluid, the intermediate article to fullysolidify, thereby forming the finished article.

In some embodiments, the build material can comprise a polymericmaterial, such as at least one from among thermoplastic polymer,thermosetting polymers, acrylonitrile-butadiene-styrene, polyurethane,acrylic, poly(acrylonitrile), polyolefins, polyvinyl chlorides, nylons,fluorocarbons, polystyrenes, polyethylene, ultra-high molecular weightpolyethylene, polypropylene, polybutene, polymethylpentene,polyisoprene, copolymers thereof, and their combinations, mixturescontaining two or more of the following polyethylene, ultra-highmolecular weight polyethylene, and polypropylene, as well as, mixturesof the foregoing with copolymers such as ethylene-butene copolymers andethylene-hexene copolymers, thermosetting plastics, such as polyimide(PI), poly amide (PA), and poly amide imide (PAI), polypropylene (PP),polyethylene (PE), ethylene vinylacetate (EVA), poly(ethyleneterephthalate) (PET), poly(vinyl acetate) (PVA), polyamide (PA), acrylicadhesives, ultraviolet (UV)/electron beam (EB)/infrared (IR) curableresin, polyether ether ketone (PEEK), polyethylene naphthalate (PEN),polyethersulfone (PES), polyphenylene sulfide (PPS), polyphenylene oxide(PPO), combinations thereof, and/or the like.

In some embodiments, the solvent can comprise at least one from amongdimethyl sulfoxide (DMSO), dimethylformamide (DMF), acetonitrile,ethanol, combinations thereof, and/or the like.

In some embodiments, such as when the nebulized coagulation agent onlypartially coagulates the liquid build material to form an intermediatepart, the intermediate part can be immersed, submerged, dipped, sprayedwith, coated with, or otherwise exposed to a coagulation solution tofully solidify the intermediate part into the finished article. Thecoagulation solution can comprise any suitable material, for instanceone or more of water, deionized water, ethanol, or the like.

It should be appreciated that all combinations of the foregoing conceptsand additional concepts discussed in greater detail below (provided suchconcepts are not mutually inconsistent) are contemplated as being partof the inventive subject matter disclosed herein. In particular, thecombinations of claimed subject matter appearing at the end of thisdisclosure are contemplated as being part of the inventive subjectmatter disclosed herein. It should be appreciated that terminologyexplicitly employed herein that also may appear in any disclosureincorporated by reference should be accorded a meaning consistent withthe particular concepts disclosed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The skilled artisan will understand that the drawings primarily are forillustrative purposes and are not intended to limit the scope of theinventive subject matter described herein. The drawings are notnecessarily to scale; in some instances, various aspects of theinventive subject matter disclosed herein may be shown exaggerated orenlarged in the drawings to facilitate an understanding of differentfeatures. In the drawings, like reference characters generally refer tolike features (e.g., functionally similar and/or structurally similarelements).

FIG. 1 provides a process flow diagram of a method for three-dimensional(3D) printing, according to an embodiment of the present disclosure.

FIG. 2 provides a schematic illustration of an apparatus for 3Dprinting, according to an embodiment of the present disclosure.

FIG. 3 provides a schematic of an exemplary computing device configuredto 3D print according to any of the approaches or methods of the presentdisclosure.

FIG. 4 provides a schematic of an exemplary computing device configuredto 3D print according to any of the approaches or methods of the presentdisclosure.

FIG. 5 provides a process flow diagram of a method of 3D printing,according to an embodiment of the present disclosure.

FIG. 6 provides a process flow diagram of a method of 3D printing,according to an embodiment of the present disclosure.

FIG. 7 provides a process flow diagram of a method of 3D printing,according to an embodiment of the present disclosure.

FIG. 8 provides a schematic of an exemplary apparatus forsolvent-assisted 3D printing of a polymer build material directly inair, according to an embodiment of the present disclosure.

FIG. 9 illustrates a printing sequence for 3D printing a vase-likearticle and a 3D printed bulky part, according to some embodiments ofthe present disclosure.

DETAILED DESCRIPTION

Various embodiments of the present disclosure will now be described morefully hereinafter with reference to the accompanying drawings, in whichsome, but not all embodiments of the inventions are shown. Indeed, theseinventions may be embodied in many different forms and should not beconstrued as limited to the embodiments set forth herein; rather, theseembodiments are provided so that this disclosure will satisfy applicablelegal requirements. The term “or” is used herein in both the alternativeand conjunctive sense, unless otherwise indicated. The terms“illustrative” and “exemplary” are used to be examples with noindication of quality level. Like numbers refer to like elementsthroughout.

As used herein, the terms “instructions,” “file,” “designs,” “data,”“content,” “information,” and similar terms may be used interchangeably,according to some example embodiments of the present invention, to referto data capable of being transmitted, received, operated on, displayed,and/or stored. Thus, use of any such terms should not be taken to limitthe spirit and scope of the disclosure. Further, where a computingdevice is described herein to receive data from another computingdevice, it will be appreciated that the data may be received directlyfrom the other computing device or may be received indirectly via one ormore computing devices, such as, for example, one or more servers,relays, routers, network access points, base stations, and/or the like.

As used herein, the term “computer-readable medium” as used hereinrefers to any medium configured to participate in providing informationto a processor, including instructions for execution. Such a medium maytake many forms, including, but not limited to a non-transitorycomputer-readable storage medium (for example, non-volatile media,volatile media), and transmission media. Transmission media include, forexample, coaxial cables, copper wire, fiber optic cables, and carrierwaves that travel through space without wires or cables, such asacoustic waves and electromagnetic waves, including radio, optical andinfrared waves. Signals include man-made transient variations inamplitude, frequency, phase, polarization or other physical propertiestransmitted through the transmission media. Examples of non-transitorycomputer-readable media include a floppy disk, a flexible disk, harddisk, magnetic tape, any other non-transitory magnetic medium, a compactdisc read only memory (CD-ROM), compact disc compact disc-rewritable(CD-RW), digital versatile disc (DVD), Blu-Ray, any other non-transitoryoptical medium, punch cards, paper tape, optical mark sheets, any otherphysical medium with patterns of holes or other optically recognizableindicia, a random access memory (RAM), a programmable read only memory(PROM), an erasable programmable read only memory (EPROM), aFLASH-EPROM, any other memory chip or cartridge, a carrier wave, or anyother non-transitory medium from which a computer can read. The termcomputer-readable storage medium is used herein to refer to anycomputer-readable medium except transmission media. However, it will beappreciated that where embodiments are described to use acomputer-readable storage medium, other types of computer-readablemediums may be substituted for or used in addition to thecomputer-readable storage medium in alternative embodiments. By way ofexample only, a design file for a printed article may be stored on acomputer-readable medium and may be read by a computing device, such asdescribed hereinbelow, for controlling part or all of a 3D printingprocess and associated apparatuses and components, according to variousembodiments described herein.

As used herein, the term “circuitry” refers to all of the following: (a)hardware-only circuit implementations (such as implementations in onlyanalog and/or digital circuitry); (b) to combinations of circuits andcomputer program product(s) comprising software (and/or firmwareinstructions stored on one or more computer readable memories), such as(as applicable): (i) to a combination of processor(s) or (ii) toportions of processor(s)/software (including digital signalprocessor(s)), software, and memory(ies) that work together to cause anapparatus, such as a mobile phone or server, to perform variousfunctions described herein); and (c) to circuits, such as, for example,a microprocessor(s) or a portion of a microprocessor(s), that requiresoftware or firmware for operation, even if the software or firmware isnot physically present. This definition of “circuitry” applies to alluses of this term in this application, including in any claims. As afurther example, as used in this application, the term “circuitry” wouldalso cover an implementation of merely a processor (or multipleprocessors) or portion of a processor and its (or their) accompanyingsoftware and/or firmware. The term “circuitry” would also cover, forexample and if applicable to the particular claim element, a basebandintegrated circuit or applications processor integrated circuit for amobile phone or a similar integrated circuit in a server, a cellularnetwork device, other network device, and/or other computing device.

As used herein, the term “computing device” refers to a specialized,centralized device, network, or system, comprising at least a processorand a memory device including computer program code, and configured toprovide guidance or direction related to the charge transactions carriedout in one or more charging networks.

As used herein, the terms “about,” “substantially,” and “approximately”generally mean plus or minus 10% of the value stated, e.g., about 250 μmwould include 225 μm to 275 μm, about 1,000 μm would include 900 μm to1,100 μm. Any provided value, whether or not it is modified by termssuch as “about,” “substantially,” or “approximately,” all refer to andhereby disclose associated values or ranges of values thereabout, asdescribed above.

Additive manufacturing, also referred to as three-dimensional (3D)printing, encompasses a range of technologies used to fabricate parts bybuilding material up rather than by subtracting unwanted material awayfrom a bulk starting workpiece. Conventionally, printed parts are formedusing 3D printing by depositing and/or solidifying a build materiallayer-by-layer in computer-controlled patterns generated from a digitalpart model; each layer forms a thin slice of the complete part and thelayers are integrated to form a tangible part based at least in part onthe digital model. Another conventional 3D printing technique is fuseddeposition modeling (FDM), a widely implemented type of 3D printing, inwhich a thermoplastic build material in the form of a filament is meltedand extruded from a hot tip to generate 3D parts layer-by-layer in acontrolled spatial pattern; as in other 3D printing processes, the partis first generated as a computer model, then transformed into commandsfor a printer. FDM can be used for fabricating prototypes and productsfrom rigid thermoplastic polymer materials, such as poly(lactic acid)(PLA) and acrylonitrile-butadiene-styrene (ABS).

Additive manufacturing is a powerful tool for production and prototypingusing a wide range of materials. Conventional 3D printing methods, forinstance conventional FDM methods, may be suitable for a limited rangeof polymeric materials and geometries, however there are many articles,materials, and production scenarios for which using such conventional 3Dprinting approaches compromises article printing precision, articlemechanical properties, and/or the cost/time associated with production.

For many or most conventional 3D printing methods, such as FDM, thethermoplastic properties of polymer materials at moderately or highlyelevated temperatures is key to their successful implementation.Unfortunately, some engineering polymers may require high temperature tobe plastic for FDM printing. For example, polyether ether ketone (PEEK)has a melting point of 343° C., which may be difficult to beimplemented. For some applications, the thermal gradient duringhigh-temperature FDM printing might be undesirable as it may inducematerial degradation due to the thermal stress. In addition, the thermalresidual stresses within printed parts may result in warpage and otherdefects. As the demand of customized polymer parts keeps growing, thereis a critical need to develop alternative polymer printing process thatcan overcome the aforementioned temperature-related setbacks.

Typically, since conventional 3D printing methods such as FDM methodsinvolve melting the 3D printing/build material to enable iterative,layered deposition, the high heat required for melting theprinting/build materials (typically a polymer) may result in thermaldamage to the polymer (molecular degradation) as well as undesirablethermal residual stress. For instance, certain polymeric materials suchas non-thermoplastic polymers may degrade upon heating instead ofmelting. Thus, these materials cannot or should not be melt processed.Other materials are difficult to handle in the filament form necessaryfor conventional FDM since they are prone to damage from the feedmechanism, stretching, distortion, and irregular flow; all of which canresult in inconsistent printing performance and unpredictable partproperties. Other drawbacks of FDM and other methods can include, butare not limited to, elevated energy consumption, limitations with regardto material selection, and residual thermal stress. Also, it cansometimes be difficult to FDM print high-temperature engineeringpolymers. For instance, even if high temperature plasticity isachievable for most polymers, the thermal residual stress within FDMparts is typically a concern. Such thermal residual stress within FDMparts may be a result of thermal gradients between individual depositedlayers and between the printed part and its surroundings. Oftentimes,such thermal residual stress can lead to deformation of an FDM part, canlead to deficient mechanical properties, can reduce the mechanical,optical, thermal, radiative, and/or chemical stability of the FDM part,and/or can lead to aesthetic and/or operability issues. Suchdeficiencies and issues may present themselves at some time after FDMprinting of the FDM part, or may present themselves, alone or incombination with other issues, sometime after FDM printing, such asafter some amount of use of the part or after some exposure of the FDMpart to an environmental or a man-made stimulus.

Additionally, undesirable surface and interface characteristics at theinterface between two neighboring filaments or layers may reduce themechanical strength and other mechanical properties of the finishedarticle. As such, FDM often results in a finished part that has reducedinternal mechanical strength, which can lead to a reduction in theoverall mechanical properties of the FDM printed part or portionsthereof.

Furthermore, current FDM technology generally requires the use of atemporary support material which is printed alongside the part to ensurethat overhanging regions and other details remain intact, especially forsoft polymer build materials but also often for other build materials.This requirement for support structures to be concurrently printed withthe finished article increases the complexity of the printing machinerysince it must handle multiple materials, the complexity of the code toappropriately deposit the support material, the fabrication time sinceswitching heads and printing support structures are both time consuming,and the post-processing time since the support material must be removedafter printing is complete. Thus, a more robust methodology for 3Dprinting engineering polymers including soft and/or non-thermoplasticmaterials is of great interest. It is desired that this process beimplementable in ambient conditions to avoid thermal residual stress onthe printed article, minimize interfaces between filaments or layers,and reduce the use of printed support structures to maximize fabricationefficiency.

Other approaches, such as those described in U.S. patent applicationSer. Nos. 16/703,686 and 16/707,087, the entire disclosure of each ofwhich are hereby incorporated herein by reference in their entireties,may rely upon a yield-stress support bath, in to which a polymeric inkis injected such that the ink retains its form during printing. However,the use of a semi-solid or viscous liquid, such as a yield-stresssupport bath or the like, into which ink is printed, may be a relativelyslow process, may require the use of a lot of materials during printing,may require additional steps or materials (e.g., preparing theyield-stress support bath using materials specifically chosen to bechemically suitable to support the ink being used, transferring theyield-stress support bath into a coagulation bath before the printedpart can be removed, and the like), often requires the addition of arheological modifier to the ink or the support bath, and/or may belimited with regard to the polymer/solvent combinations that arepossible based on the chemistry and rheology of a support bath. As such,there is a desire for more rapid, more flexible, and less materialintensive freeform printing of 3D polymer articles.

Thus, the inventors have conceived of and diligently reduced to practicemultiple embodiments of a method and an associated apparatus forthree-dimensional (3D) printing that enables freeform fabrication ofprinted structures and articles. According to some embodiments, suchfreeform fabrication can be carried out under ambient conditions.According to these and/or other embodiments, such freeform fabricationcan be carried out without the use of support structures (e.g., printedsupport structures, solid support structures, support structures thatare inherent to the printed article or the printing platform, supportstructures that should or must be removed after printing and before theprinted article is ready for use, and/or the like). According to someembodiments, a build material (e.g., a polymeric material) can bedissolved in a solvent, a solvent mixture, or a mixture of solvent(s)with non-solvents (e.g., a rheological modifier and/or the like) forprinting according to a variety of possible printing methods (e.g.,extrusion, injection, etc.) within an air-filled volume.

In some embodiments, a solvent-assisted printing process is provided fordirectly printing polymers at room temperature. In some embodiments, thesolvent-assisted printing process can include dissolving a polymericmaterial in a solvent or the like for use as an ink for printing. Insome embodiments, the solvent-assisted printing process can furtherinclude printing the resulting ink directly in air at room temperaturein an enclosed chamber using a proper dispensing mechanism while acoagulant/non-solvent is delivered to the part being printed thatpartially solidifies the part. Without wishing to be bound by anyparticular theory, solidification may occur in the presence of theproper coagulant/non-solvent or mixture thereof due to a phase inversionmechanism. In other embodiments, without wishing to be bound by anyparticular theory, the coagulation agent can cause partial,substantially complete, or complete coagulation, solidification,polymerization, phase inversion, cross-linking, crystallization,calcification, concretion, setting, stiffening, hardening, amalgamation,strengthening, gelation, congealing, thickening, densification,annealing, shaping, forming, clotting, variations thereof, combinationsthereof, or the like. In some embodiment, if needed, the printed partcan be post-processed in a solidification bath or the like for completesolidification. In some embodiments, the consumed solvent can bereclaimed for recycling and reuse. By way of example only,acrylonitrile-butadiene-styrene (ABS) can be dissolved in dimethylsulfoxide (DMSO) and the resulting ABS-DMSO mixture solution (e.g., the“ink”) can be extruded in air while a volume of water is delivered as acoagulant using a nebulizer. In some embodiments, after printing, thepart can be submerged into a water bath for further or completesolidification. In some embodiments, the part can then be removed fromthe water-based solidification bath and dried at room temperature whilethe residual solvent can be reclaimed from the water-basedsolidification bath, e.g., through a distillation process. In someembodiments, continuous conduits, shells, bulky parts, complex parts,hollow parts, and the like can be printed according to a solvent-enableddirect printing in air method. While extrusion is used as the printingmodality described in most embodiments of the present disclosure, thebuild material/solvent mixture solution can also be printed using otherapplicable printing modalities including but not limited to inkjettingor the like.

The build material/solvent solution (which is also referred tointerchangeably herein as the “ink,” the “printing mixture,” the“printing medium,” the “polymer mixture,” and the “polymer solution,”)can be printed directly into air without the use of solid or liquidsupport, such as concurrently printed solid supports or a yield-stresssupport bath, thereby forming an entire 3D part in air without heatingthe build material during printing, without requiring the printed buildmaterial to cool, and without requiring the use of solid or liquidsupports during printing of the article/part, which typically need to beremoved after printing. After printing, the printed article can beimmersed in a post-printing coagulation solution to solidify the printedpolymer material, thereby forming the solid printed article/part.

In some embodiments, 3D printed structures and articles may befabricated under ambient conditions and/or without the use of printedsupport structures which would need to be removed after 3D printing inorder to achieve the finished structure or article. In some embodiments,a build material can be dissolved in a suitable solvent or solventsolution (e.g., solvent/non-solvent mixture) such that the resultingsolution is a suitable ink for 3D printing. In some embodiments, thebuild material can comprise one or more polymers or a polymer solution.In some embodiments, the ink, comprising the build material, can bedisposed within a printing volume or onto a printing platform withoutthe use of supports or other structures being previously, concurrently,or subsequently printed to support the build material while the buildmaterial solidifies. In some embodiments, the method can comprisedelivering ink or build material into the printing environment,communicating ink or build material into the printing environment,causing transfer of ink or build material into the printing environment,conveying ink or build material into the printing environment, printingink or build material into the printing environment, extruding ink orbuild material into the printing environment, dispersing ink or buildmaterial into the printing environment, injecting ink or build materialinto the printing environment, spraying ink or build material into theprinting environment, and/or the like. In some embodiments, thedisclosed freeform printing methods and approaches may be carried out atambient temperature and pressure.

In some embodiments, just previous to, concurrent with, or justfollowing the disposition of ink into the printing volume or onto theprinting platform, a volume of a coagulation agent, such as a coagulant,coagulant solution, a non-solvent, variations thereof, or combinationsthereof, can be disposed, such as by an aerosol sprayer or othersuitable dispensing mechanism, to a location, point, or volume about,e.g., directly adjacent to, the disposed ink. In some embodiments, themethod can comprise delivering coagulation agent into the printingenvironment, communicating coagulation agent into the printingenvironment, causing transfer of coagulation agent into the printingenvironment, conveying coagulation agent into the printing environment,printing coagulation agent into the printing environment, extrudingcoagulation agent into the printing environment, dispersing coagulationagent into the printing environment, injecting coagulation agent intothe printing environment, spraying coagulation agent into the printingenvironment, and/or the like.

Without wishing to be bound by any particular theory, the coagulationagent can cause partial, substantially complete, or completecoagulation, solidification, polymerization, phase inversion,cross-linking, crystallization, calcification, concretion, setting,stiffening, hardening, amalgamation, strengthening, gelation,congealing, thickening, densification, annealing, shaping, forming,clotting, variations thereof, combinations thereof, or the like. Assuch, a first volume of ink can be printed, e.g., by a nozzle or thelike, in a freeform manner directly into air and partially or fullysolidified by disposing a first volume of the coagulation agentsufficiently close by the printed ink, the nozzle can move a distance,in a particular direction, from the previous printing location and printa second volume of ink, e.g., adjacent the first volume of ink (nowpartially or fully solidified), dispose a second volume of thecoagulation agent to partially or fully solidify the second volume ofink, and continue along a predetermined path through the printing volumeor across the printing platform in order to completely print anintermediate or finished article without being required to melt thebuild material, use support structures, or use a support bath or thelike to maintain the structure of the printed article prior tocompletion of printing of the article. In some embodiments, anintermediate article may be one in which some or all of the article isonly partially solidified or for which further processing is helpful orrequired to achieve the finished article.

In some embodiments, if an intermediate article is formed, heat, achemical reactant, electromagnetic radiation, and/or the like may beused to fully solidify or otherwise process the intermediate article toform the finished article.

In some embodiments, a method for three-dimensional printing of aprinted article can comprise forming a liquid build material, the liquidbuild material comprising a polymeric material in a solvent; disposingthe liquid build material into a volume of air; and spraying a nebulizedcoagulation agent within a predetermined distance of the disposed liquidbuild material to at least partially coagulate the liquid buildmaterial, thereby forming the article. In some embodiments, spraying thenebulized coagulation agent within the predetermined distance of thedisposed liquid build material is done within a predetermined timefollowing the disposing the liquid build material into the volume ofair. In some embodiments, spraying the nebulized coagulation agentwithin the predetermined distance of the disposed liquid build materialwithin the predetermined time following the disposing the liquid buildmaterial into the volume of air only partially coagulates the liquidbuild material, the method further comprising: exposing the intermediatearticle to a post-printing coagulation solution to fully solidify theintermediate article, forming the finished article. In some embodiments,exposing the intermediate article to the post-printing coagulationsolution comprises submerging the intermediate article in a bath of thepost-printing coagulation solution. In some embodiments, the methodfurther comprises dissolving the polymeric material in the solvent toform the liquid build material. In some embodiments, at least one of theforming, the disposing, the spraying, or the exposing is carried out byan apparatus comprising one or more reservoirs configured to contain asupply of the liquid build material, a nozzle, and a computing device.In some embodiments, the nozzle is configured and dimensioned to movealong a predetermined path within the volume of air to dispose a volumeof the liquid build material. In some embodiments, the predeterminedpath is determined by the computing device based upon an input designfile comprising a design of the finished article. In some embodiments,the apparatus is configured to communicate the liquid build materialfrom the reservoir, through the nozzle, and into the volume of air. Insome embodiments, the intermediate article is formed free of printedsupport structures.

In some embodiments, the method can further comprise, optionally,dissolving a polymeric material in a solvent to form the build material(e.g., “the liquid build material,” “the ink,” or “the polymericsolution”). In some embodiments, the build material can comprise anysuitable polymeric material such as a thermoplastic. In someembodiments, a polymeric material can be dissolved or dispersed in anysuitable solvent. In some embodiments, such a solvent can comprisedimethyl sulfoxide (DMSO), and/or the like. In some embodiments, to formthe build material, the polymeric material can be dissolved in thesolvent partially or fully, at about room temperature (about 20° C. toabout 25° C.), or at an elevated temperature, while being stirred,shaken, agitated, bombarded with electromagnetic radiation and/orultrasonic sound waves, or the like. In some embodiments, one or moresolvents can be chosen that are capable of breaking down the buildmaterial without causing molecular degradation or a reduction in thedegree of polymerization (DP). Conventional additive manufacturing and3D printing techniques for polymeric materials typically requiresmelting the polymeric material at least partially if not fully tofacilitate the communication and build-up of the article using thepolymeric material. These conventional additive manufacturing and 3Dprinting techniques for polymeric materials can require high heat, whichcan make the process costly, dangerous, time-consuming, and limiting interms of the reusability of printing materials. By contrast, the roomtemperature process according to some embodiments described hereinrequires no heating of the printing materials, no thermal deteriorationof the polymers, and can eliminate the process step from conventionaladditive manufacturing and 3D printing methods of heating and/or meltingthe polymeric material.

According to another embodiment, a method can be provided for 3Dprinting an article that comprises: disposing a first volume of a liquidbuild material onto a substrate; within a predetermined time followingdisposing the first volume of the liquid build material onto thesubstrate, spraying a first volume of a nebulized coagulation agentwithin a predetermined distance of the disposed first volume of theliquid build material to at least partially coagulate the first volumeof the first volume of the liquid build material; disposing a secondvolume of the liquid build material onto at least a portion of the atleast partially coagulated first volume of the liquid build material;and within the predetermined time following disposing the second volumeof the liquid build material onto at least the portion of the at leastpartially coagulated first volume of the liquid build material, sprayinga second volume of the nebulized coagulation agent within thepredetermined distance of the disposed second volume of the liquid buildmaterial to at least partially coagulate the second volume of the liquidbuild material. In some embodiments, spraying the first volume and thesecond volume of the nebulized coagulation agent within thepredetermined distance of the disposed first and second volumes of theliquid build material only partially coagulates the liquid buildmaterial, the method further comprising: exposing the article to apost-printing coagulation solution to fully solidify the article. Insome embodiments, exposing the article to the post-printing coagulationsolution comprises submerging the article in a bath of the post-printingcoagulation solution. In some embodiments, the liquid build materialcomprises at least one polymeric material and at least one solvent. Insome embodiments, the method can be carried out by an apparatuscomprising one or more reservoirs configured to contain a supply of theliquid build material, a nozzle, and a computing device. In someembodiments, the nozzle is configured and dimensioned to move along apredetermined path within the volume of air to dispose a volume of theliquid build material. In some embodiments, the predetermined path isdetermined by the computing device based upon an input design filecomprising a design of the finished article. In some embodiments, theapparatus can be configured to communicate the liquid build materialfrom the reservoir, through the nozzle, and into the volume of air.

As such, according to another embodiment, an apparatus can be providedfor 3D printing a finished article. In some embodiments, the apparatuscan comprise: a printing space comprising an air-filled inner volume anda printing substrate; a reservoir configured to contain a supply of aliquid build material; a nozzle coupled to the reservoir and configuredto dispose a volume of the liquid build material into the air-filledinner volume of the printing space; a nebulizer configured to nebulize acoagulation agent and disperse the nebulized coagulation agent within apredetermined distance of the disposed volume of liquid build materialto at least partially coagulate the disposed volume of liquid buildmaterial; and a computing device configured to control movement of thenozzle and the disposing of the volume of the liquid build material intothe air-filled inner volume of the printing space. In some embodiments,the nebulized coagulation agent may only partially coagulate thedisposed volume of liquid build material to form an intermediatearticle. As such, in some embodiments, the apparatus can furthercomprise, optionally, a solidification bath comprising a coagulationfluid, the solidification bath configured to receive the intermediatearticle, the coagulation fluid operable to fully solidify the article,if needed, thereby forming the finished article.

In some embodiments, the build material can comprise a polymericmaterial, such as at least one from among thermoplastic polymer,thermosetting polymers, acrylonitrile-butadiene-styrene, polyurethane,acrylic, poly(acrylonitrile), polyolefins, polyvinyl chlorides, nylons,fluorocarbons, polystyrenes, polyethylene, ultra-high molecular weightpolyethylene, polypropylene, polybutene, polymethylpentene,polyisoprene, copolymers thereof, and their combinations, mixturescontaining two or more of the following polyethylene, ultra-highmolecular weight polyethylene, and polypropylene, as well as, mixturesof the foregoing with copolymers such as ethylene-butene copolymers andethylene-hexene copolymers, thermosetting plastics, such as polyimide(PI), poly amide (PA), and poly amide imide (PAI), polypropylene (PP),polyethylene (PE), ethylene vinylacetate (EVA), poly(ethyleneterephthalate) (PET), poly(vinyl acetate) (PVA), polyamide (PA), acrylicadhesives, ultraviolet (UV)/electron beam (EB)/infrared (IR) curableresin, polyether ether ketone (PEEK), polyethylene naphthalate (PEN),polyethersulfone (PES), polyphenylene sulfide (PPS), polyphenylene oxide(PPO), combinations thereof, and/or the like.

In some embodiments, the solvent can comprise at least one from amongdimethyl sulfoxide (DMSO), dimethylformamide (DMF), acetonitrile,ethanol, combinations thereof, and/or the like.

In some embodiments, such as when the nebulized coagulation agent onlypartially coagulates the liquid build material to form an intermediatepart, the intermediate part can be immersed, submerged, dipped, sprayedwith, coated with, or otherwise exposed to a coagulation solution tofully solidify the intermediate part into the finished article. Thecoagulation solution can comprise any suitable material, for instanceone or more of water, deionized water, ethanol, or the like.

Referring now to FIG. 1 , a process 10 is described for room-temperaturepolymer printing of polymeric structures, directly in air, withoutneeding to heat the polymer build materials to a plastic state.According to some embodiments, the process 10 comprises providing asolvent-polymer mixture 11 suitable for dissolution 12 a of the polymerin the solvent to form the ink 12 b (e.g., “the build material”). Insome embodiments, the process 10 further comprises depositing the ink 12b into a printing environment in the presence of a coagulant 13,resulting in coagulation, e.g., due to phase inversion, andself-supported printing 14 of the ink 12 b. In some embodiments, the ink12 b is deposited in air in the form of viscous filaments or dropletswhile a coagulation agent/non-solvent 13, e.g., a coagulation agent ornon-solvent having a higher Hansen solubility/affinity value with thesolvent of the ink 12 b than that of the polymer has, can be deliveredsimultaneously in the enclosed printing environment, e.g., a 3D printingchamber. The coagulant 13 can cause partial or full coagulation of theink 12 b during printing 14, resulting in formation of the partially orfully solidified part 15. In an instance in which the partially or fullysolidified part 15 is only partially solidified after exposure to thecoagulant 13, the process 10 can further comprise exposing the partiallysolidified part 15 to a post-printing solidification bath 16 a in orderto remove solvent out of polymer parts completely, causing fullsolidification 16 b of the part, thereby forming the fully solidifiedpart 16 c. In some embodiments, once the fully solidified part 16 c isprinted and solidified in the post-printing solidification bath 16 a,the fully solidified part 16 c can be removed from the post-printingsolidification bath 16 a, and the solvent can be recycled 17 from theprinting environment and/or the post-printing solidification bath 16 aand reclaimed 18 for reuse during subsequent 3D printing processes. Therecycling 17 process can comprise removing all liquid from the printingenvironmental and/or the post-printing solidification bath and thereclamation 18 process can comprise a distillation process wherebymaterials are separated based upon the temperature at which phase changeoccurs which is inherent between different materials.

As compared to conventional 3D polymer printing technologies such asFDM, the described 3D printing processes and methods, and associatedsystems, apparatuses, and computer program products, have at least thefollowing advantages: 1) no required size or form of raw polymermaterials. 2) no pre-heating process and room-temperature printing, and3) reduced energy consumption (e.g., for heating).

As described herein, 3D extrusion printing of various polymer parts inair has been successfully carried out to demonstrate the technologyfeasibility. In some embodiments, suitable materials can include but arenot limited to: acrylonitrile butadiene styrene (ABS) as a buildpolymer, dimethyl sulfoxide (DMSO) as a solvent, and water as acoagulation agent; the residual solvent in the post-printingsolidification bath is reclaimed using distillation.

According to other embodiments, a polymer printing process can beprovided that comprises dissolving a polymer build material with asuitable solvent in order to obtain a homogeneous ink solution forprinting, using an applicable 3D printer (e.g., extrusion-based,inkjetting-based, etc.). In some embodiments, the ink can be dispensedin a filament or droplet form for layer-by-layer deposition. In someembodiments, the printing process can be carried in an enclosed chamber(e.g., “printing environment”) to collect any solvent from thesolvent-containing ink that is released during at least partialcoagulation of the ink. Simultaneously, a coagulation agent can bedelivered to the environment where the polymer part is being printed,partially solidifying deposited features. Without wishing to be bound byany particular theory, the solidification process may be carried out dueto or according to a phase inversion, where the solvent is removed froma liquid-polymer solution to solidify the polymer. In some embodiments,the phase inversion process may start on the outer surface of depositedfilaments/droplets as this is in direct contact with the activecoagulation agent in the printing environment. Once the surface iscoagulated, the coagulation front may travel some distance inwardsthrough the filament/droplet through diffusion and remove the solventout of the printed structure due to the higher affinity between thesolvent and the selected coagulation agent. This in-processsolidification mechanism may be controlled to occur only partially for abalance of good fusion between two consecutively deposited layers due tounsolidified polymer solution and enough strength to hold a printedstructure in air due to solidified polymer, which may result in theformation of an intermediate part or intermediate article. The printedpart may have heterogeneous stiffness right after printing since layerslocated at the bottom are stiffer due to a higher solidification ratio,which may be a result of the longer exposure to the coagulation agent.For complete solidification throughout the intermediate part, it can beimmersed, if needed, in a post-printing solidification bath to fullyremove the solvent. In some embodiments, the collected solvent orsolvent-containing solution from the printing chamber and/orpost-printing solidification bath can be collected, recycled, and/orpost-processed in order to reclaim the solvent for reuse, minimizing thecost, material intensity, and environmental impact of 3D printing ascompared to conventional 3D printing approaches.

Computer Program Products, Methods, and Computing Entities

Embodiments of the present invention may be implemented in various ways,including as computer program products that comprise articles ofmanufacture. Such computer program products may include one or moresoftware components including, for example, software objects, methods,data structures, or the like. A software component may be coded in anyof a variety of programming languages. An illustrative programminglanguage may be a lower-level programming language such as an assemblylanguage associated with a particular hardware architecture and/oroperating system platform. A software component comprising assemblylanguage instructions may require conversion into executable machinecode by an assembler prior to execution by the hardware architectureand/or platform. Another example programming language may be ahigher-level programming language that may be portable across multiplearchitectures. A software component comprising higher-level programminglanguage instructions may require conversion to an intermediaterepresentation by an interpreter or a compiler prior to execution.

Other examples of programming languages include, but are not limited to,a macro language, a shell or command language, a job control language, ascript language, a database query or search language, and/or a reportwriting language. In one or more example embodiments, a softwarecomponent comprising instructions in one of the foregoing examples ofprogramming languages may be executed directly by an operating system orother software component without having to be first transformed intoanother form. A software component may be stored as a file or other datastorage construct. Software components of a similar type or functionallyrelated may be stored together such as, for example, in a particulardirectory, folder, or library. Software components may be static (e.g.,pre-established or fixed) or dynamic (e.g., created or modified at thetime of execution).

A computer program product may include a non-transitorycomputer-readable storage medium storing applications, programs, programmodules, scripts, source code, program code, object code, byte code,compiled code, interpreted code, machine code, executable instructions,and/or the like (also referred to herein as executable instructions,instructions for execution, computer program products, program code,and/or similar terms used herein interchangeably). Such non-transitorycomputer-readable storage media include all computer-readable media(including volatile and non-volatile media).

In one embodiment, a non-volatile computer-readable storage medium mayinclude a floppy disk, flexible disk, hard disk, solid-state storage(SSS) (e.g., a solid-state drive (SSD), solid state card (SSC), solidstate module (SSM), enterprise flash drive, magnetic tape, or any othernon-transitory magnetic medium, and/or the like. A non-volatilecomputer-readable storage medium may also include a punch card, papertape, optical mark sheet (or any other physical medium with patterns ofholes or other optically recognizable indicia), compact disc read onlymemory (CD-ROM), compact disc-rewritable (CD-RW), digital versatile disc(DVD), Blu-ray disc (BD), any other non-transitory optical medium,and/or the like. Such a non-volatile computer-readable storage mediummay also include read-only memory (ROM), programmable read-only memory(PROM), erasable programmable read-only memory (EPROM), electricallyerasable programmable read-only memory (EEPROM), flash memory (e.g.,Serial, NAND, NOR, and/or the like), multimedia memory cards (MMC),secure digital (SD) memory cards, SmartMedia cards, CompactFlash (CF)cards, Memory Sticks, and/or the like. Further, a non-volatilecomputer-readable storage medium may also include conductive-bridgingrandom access memory (CBRAM), phase-change random access memory (PRAM),ferroelectric random-access memory (FeRAM), non-volatile random-accessmemory (NVRAM), magnetoresistive random-access memory (MRAM), resistiverandom-access memory (RRAM), Silicon-Oxide-Nitride-Oxide-Silicon memory(SONOS), floating junction gate random access memory (FJG RAM),Millipede memory, racetrack memory, and/or the like.

In one embodiment, a volatile computer-readable storage medium mayinclude random access memory (RAM), dynamic random access memory (DRAM),static random access memory (SRAM), fast page mode dynamic random accessmemory (FPM DRAM), extended data-out dynamic random access memory (EDODRAM), synchronous dynamic random access memory (SDRAM), double datarate synchronous dynamic random access memory (DDR SDRAM), double datarate type two synchronous dynamic random access memory (DDR2 SDRAM),double data rate type three synchronous dynamic random access memory(DDR3 SDRAM), Rambus dynamic random access memory (RDRAM), TwinTransistor RAM (TTRAM), Thyristor RAM (T-RAM), Zero-capacitor (Z-RAM),Rambus in-line memory module (RIMM), dual in-line memory module (DIMM),single in-line memory module (SIMM), video random access memory (VRAM),cache memory (including various levels), flash memory, register memory,and/or the like. It will be appreciated that where embodiments aredescribed to use a computer-readable storage medium, other types ofcomputer-readable storage media may be substituted for or used inaddition to the computer-readable storage media described above.

As should be appreciated, various embodiments of the present inventionmay also be implemented as methods, apparatus, systems, computingdevices, computing entities, and/or the like. As such, embodiments ofthe present invention may take the form of an apparatus, system,computing device, computing entity, and/or the like executinginstructions stored on a computer-readable storage medium to performcertain steps or operations. Thus, embodiments of the present inventionmay also take the form of an entirely hardware embodiment, an entirelycomputer program product embodiment, and/or an embodiment that comprisescombination of computer program products and hardware performing certainsteps or operations.

Embodiments of the present invention are described below with referenceto block diagrams and flowchart illustrations. Thus, it should beunderstood that each block of the block diagrams and flowchartillustrations may be implemented in the form of a computer programproduct, an entirely hardware embodiment, a combination of hardware andcomputer program products, and/or apparatus, systems, computing devices,computing entities, and/or the like carrying out instructions,operations, steps, and similar words used interchangeably (e.g., theexecutable instructions, instructions for execution, program code,and/or the like) on a computer-readable storage medium for execution.For example, retrieval, loading, and execution of code may be performedsequentially such that one instruction is retrieved, loaded, andexecuted at a time. In some exemplary embodiments, retrieval, loading,and/or execution may be performed in parallel such that multipleinstructions are retrieved, loaded, and/or executed together. Thus, suchembodiments can produce specifically-configured machines performing thesteps or operations specified in the block diagrams and flowchartillustrations. Accordingly, the block diagrams and flowchartillustrations support various combinations of embodiments for performingthe specified instructions, operations, or steps.

Exemplary Systems and Apparatuses

FIG. 2 provides, according to one or more embodiments of the presentdisclosure, an exemplary apparatus 20 for solvent-assisted polymeric 3Dprinting at ambient temperature and pressure, without the use of asupport bath or solid supports, and without melting the polymeric ink torender the ink plastic for printing. The apparatus 20 comprises aprinting environment 21, which may be enclosed or open, but neverthelessdefines an inner volume 22 and comprises a printing substrate 23. Theapparatus 20 can be operably configured to 3D print a self-supportingarticle 24 supported on the printing substrate 23 and beingself-supporting across a wide degree of article complexities. Theapparatus 20 can further comprise a polymeric ink reservoir 25configured to store a supply of a polymeric ink that comprises one ormore solvents and one or more polymeric materials. In some embodiments,the polymeric ink reservoir 25 can be operably coupled to a printingnozzle 26 that is dimensioned and configured to receive, from thepolymeric ink reservoir 25, a portion or flow of the polymeric ink. Theprinting nozzle 26 can be configured to be moved in three dimensions (x,y, and z) within the inner volume 22 of the printing environment 21 andto dispose discrete volumes or continuous flows of the polymeric ink toparticular locations within the inner volume 22 that are associated withthe self-supporting article 24, as desired. Said otherwise, the printingnozzle 26 can be configured to dispose volumes or a flow of thepolymeric ink onto the printing substrate 23 or onto a previouslyprinted portion of the self-supporting article 24, in the inner volume22, e.g., an air-filled inner volume, and to move in three dimensionssuch that particular volumes of the polymeric ink are deposited atcorresponding particular points and locations such that the dimensions,form factor, and characteristics of the self-supporting article 24, oncefully printed, are in line with those desired or in line with an initialdesign for the self-supporting article 24. To do so, the printing nozzle26 may be configured to deposits the polymeric ink into the inner volume22 according to a pre-determined route or printing schedule.

In some embodiments, the apparatus 20 can further comprise a nebulizer27 configured to nebulize and disperse a coagulation agent 28 within theinner volume 22 of the printing environment 21. The nebulizer 27 can beconfigured to receive a supply of the coagulation agent 28 from acoagulation agent reservoir 29. In some embodiments, at a predeterminedtime before, during, or after the printing nozzle 26 deposits thepolymeric ink into the inner volume 22, e.g., according to thepre-determined route or printing schedule, the nebulizer 27 can beconfigured to nebulize a volume of the coagulation agent and dispersethe nebulized volume of the coagulation agent nearby the printing nozzle26 and/or nearby the deposited polymeric ink. In some embodiments, thepredetermined time may be selected from a predetermined temporal rangeon either side of the time at which the polymeric ink is deposited fromthe printing nozzle 26 into the inner volume 22 at respective particularlocations. In some embodiments, “nearby” the printing nozzle 26 or thedeposited polymeric ink may refer to a location within a predetermineddistance of the printing nozzle 26 or within a predetermined distance ofthe deposited polymeric ink. In some embodiments, the nebulizer 27 maybe configured to disperse the coagulation agent 28, once nebulized,before, during, and after deposition of the polymeric ink such thatsufficient interaction with the deposited polymeric ink and thecoagulation agent 28, once nebulized, is possible. In some embodiments,the nebulizer 27 may be configured to move in three dimensions (x, y,and z) in concert with or alignment with the movements of the printingnozzle 26. In some embodiments, more than one nozzle, e.g., such as morethan one of the printing nozzles 26, and/or more than one nebulizer,e.g., such as more than one of the nebulizer 27, may be concurrentlyused during printing, such as for printing different portions of a largeor complex article, e.g., the self-supporting article 24.

In some embodiments, the apparatus 20 may comprise or be incommunication with a computing device 30 that is operable to cause orcontrol one or more of the movements of the printing nozzle 26, theprovision of polymeric ink from the polymeric ink reservoir 25 to theprinting nozzle 26, the rate of deposition of polymeric ink from theprinting nozzle 26, the movements of the nebulizer 27, the provision ofthe coagulation agent 28 from the coagulation agent reservoir 29 to thenebulizer 27, the rate of nebulization of the coagulation agent 28 bythe nebulizer 27, the rate and/or distance of dispersal of thecoagulation agent 28 from the nebulizer 27, the commencement ortermination of printing and/or nebulization, other similar properties oractivities within or about the printing environment 21, combinationsthereof, and/or the like.

In some embodiments, the computing device 30 can comprise one or moreprocessing elements 32, one or more non-volatile memories 33, one ormore volatile memories 34, and/or one or more transmitter/receivers 38(e.g., “transceivers 38”). In some embodiments, the computing device 30is configured to store one or more computer program products, computerprogram code, a computer-readable media comprising instructions, and/orthe like. In some embodiments, the computing device 30 is configured todetermine, using a starting position, a manual input, sensors, ageospatial coordinate system, or the like, a current position of theprinting nozzle 26, the nebulizer 27, and/or the like. In someembodiments, the computing device 30 is configured to determine, usingany suitable means, the current reservoir level of the polymeric inkreservoir 25 and/or the coagulation agent reservoir 29. In someembodiments, the computing device 30 is configured to be in wired orwireless communication, such as via the transceivers 38, with one ormore motors (not shown) or the like that are configured to move theprinting nozzle 26, the nebulizer 27, or other components of theapparatus 20 within the inner volume 22 of the printing environment 21.In some embodiments, the computing device 30 can be configured tocommunicate a set of instructions to the one or more motors, or thelike, for a series of movements of the printing nozzle 26 within theinner volume 22 of the printing environment 21. In some embodiments, thecomputing device 30 can provide movement instructions to the one or moremotors, or the like, for making a series or sequence of movements of theprinting nozzle 26 which are necessary to print the self-supportingarticle 24 in its entirety. In some embodiments, the computing device 30can provide movement instructions to the one or more motors, or thelike, for making a series or sequence of movements of the nebulizer 27such that the nebulizer 27 follows the movements of the printing nozzle26 in order to achieve or maintain a distance between the nebulizer 27and the printing nozzle 26 that is sufficient to at least partiallycoagulate the polymeric build material as it is disposed from theprinting nozzle 26. In some embodiments, the computing device 30 canprovide flow rate instructions, e.g., in conjunction with movementinstructions, to one or more of the polymeric ink reservoir 25, theprinting nozzle 26, the nebulizer 27, or the coagulation agent reservoir29 in order for the proper flow rate or discrete volume of polymeric inkor the coagulation agent 28, once nebulized, is disposed or dispersed ata correct corresponding location within the inner volume 22 of theprinting environment 21 such that the apparatus 20 can achieve theself-supporting article 24, as desired.

Exemplary Computing Entity

FIG. 3 provides a schematic of the computing device 30 according to oneembodiment of the present invention. In general, the terms computingdevice, computing entity, computer, entity, device, system, and/orsimilar words used herein interchangeably may refer to, for example, oneor more computers, computing entities, desktops, mobile phones, tablets,phablets, notebooks, laptops, distributed systems, kiosks, inputterminals, servers or server networks, blades, gateways, switches,processing devices, processing entities, set-top boxes, relays, routers,network access points, base stations, the like, and/or any combinationof devices or entities adapted to perform the functions, operations,and/or processes described herein. Such functions, operations, and/orprocesses may include, for example, transmitting, receiving, operatingon, processing, displaying, storing, determining, creating/generating,monitoring, evaluating, comparing, and/or similar terms used hereininterchangeably. In one embodiment, these functions, operations, and/orprocesses can be performed on data, content, information, and/or similarterms used herein interchangeably.

As shown in FIG. 3 , in one embodiment, the computing device 30 mayinclude or be in communication with one or more processing elements 32(also referred to as processors, processing circuitry, and/or similarterms used herein interchangeably) that communicate with other elementswithin the computing device 30 via a bus, for example. As will beunderstood, the processing element 32 may be embodied in a number ofdifferent ways. For example, the processing element 32 may be embodiedas one or more complex programmable logic devices (CPLDs),microprocessors, multi-core processors, coprocessing entities,application-specific instruction-set processors (ASIPs),microcontrollers, and/or controllers. Further, the processing element 32may be embodied as one or more other processing devices or circuitry.The term circuitry may refer to an entirely hardware embodiment or acombination of hardware and computer program products. Thus, theprocessing element 32 may be embodied as integrated circuits,application specific integrated circuits (ASICs), field programmablegate arrays (FPGAs), programmable logic arrays (PLAs), hardwareaccelerators, other circuitry, and/or the like. As will therefore beunderstood, the processing element 32 may be configured for a particularuse or configured to execute instructions stored in volatile ornon-volatile media or otherwise accessible to the processing element 32.As such, whether configured by hardware or computer program products, orby a combination thereof, the processing element 32 may be capable ofperforming steps or operations according to embodiments of the presentinvention when configured accordingly.

In one embodiment, the computing device 30 may further include or be incommunication with non-volatile media (also referred to as non-volatilestorage, memory, memory storage, memory circuitry and/or similar termsused herein interchangeably). In one embodiment, the non-volatilestorage or memory may include one or more non-volatile storage or memorymedia 33, including but not limited to hard disks, ROM, PROM, EPROM,EEPROM, flash memory, MMCs, SD memory cards, Memory Sticks, CBRAM, PRAM,FeRAM, NVRAM, MRAM, RRAM, SONOS, FJG RAM, Millipede memory, racetrackmemory, and/or the like. As will be recognized, the non-volatile storageor memory media may store databases, database instances, databasemanagement systems, data, applications, programs, program modules,scripts, source code, object code, byte code, compiled code, interpretedcode, machine code, executable instructions, and/or the like. The termdatabase, database instance, database management system, and/or similarterms used herein interchangeably may refer to a collection of recordsor data that is stored in a computer-readable storage medium using oneor more database models, such as a hierarchical database model, networkmodel, relational model, entity-relationship model, object model,document model, semantic model, graph model, and/or the like.

In one embodiment, the computing device 30 may further include or be incommunication with volatile media (also referred to as volatile storage,memory, memory storage, memory circuitry and/or similar terms usedherein interchangeably). In one embodiment, the volatile storage ormemory may also include one or more volatile storage or memory media 34,including but not limited to RAM, DRAM, SRAM, FPM DRAM, EDO DRAM, SDRAM,DDR SDRAM, DDR2 SDRAM, DDR3 SDRAM, RDRAM, TTRAM, T-RAM, Z-RAM, RIMM,DIMM, SIMM, VRAM, cache memory, register memory, and/or the like. Aswill be recognized, the volatile storage or memory media may be used tostore at least portions of the databases, database instances, databasemanagement systems, data, applications, programs, program modules,scripts, source code, object code, byte code, compiled code, interpretedcode, machine code, executable instructions, and/or the like beingexecuted by, for example, the processing element 32. Thus, thedatabases, database instances, database management systems, data,applications, programs, program modules, scripts, source code, objectcode, byte code, compiled code, interpreted code, machine code,executable instructions, and/or the like may be used to control certainaspects of the operation of the computing device 30 with the assistanceof the processing element 32 and operating system.

In some embodiments, the computing device 30 may also include one ormore network interfaces, such as a transceiver 38 for communicating withvarious computing entities, such as by communicating data, content,information, and/or similar terms used herein interchangeably that canbe transmitted, received, operated on, processed, displayed, stored,and/or the like. Such communication may be executed using a wired datatransmission protocol, such as fiber distributed data interface (FDDI),digital subscriber line (DSL), Ethernet, asynchronous transfer mode(ATM), frame relay, data over cable service interface specification (DOCSIS), or any other wired transmission protocol. Similarly, the computingdevice 30 may be configured to communicate via wireless externalcommunication networks using any of a variety of protocols, such asgeneral packet radio service (GPRS), Universal Mobile TelecommunicationsSystem (UMTS), Code Division Multiple Access 2000 (CDMA2000), CDMA20001× (1×RTT), Wideband Code Division Multiple Access (WCDMA), GlobalSystem for Mobile Communications (GSM), Enhanced Data rates for GSMEvolution (EDGE), Time Division-Synchronous Code Division MultipleAccess (TD-SCDMA), Long Term Evolution (LTE), Evolved UniversalTerrestrial Radio Access Network (E-UTRAN), Evolution-Data Optimized(EVDO), High Speed Packet Access (HSPA), High-Speed Downlink PacketAccess (HSDPA), IEEE 802.11 (Wi-Fi), Wi-Fi Direct, 802.16 (WiMAX),ultra-wideband (UWB), infrared (IR) protocols, near field communication(NFC) protocols, Wibree, Bluetooth protocols, wireless universal serialbus (USB) protocols, and/or any other wireless protocol.

Although not shown, the computing device 30 may include or be incommunication with one or more input elements, such as a keyboard input,a mouse input, a touch screen/display input, motion input, movementinput, audio input, pointing device input, joystick input, keypad input,and/or the like. The computing device 30 may also include or be incommunication with one or more output elements (not shown), such asaudio output, video output, screen/display output, motion output,movement output, and/or the like.

Exemplary External Computing Entity

FIG. 4 provides an illustrative schematic representative of an externalcomputing device 400 that can be used in conjunction with embodiments ofthe present invention. In general, the terms device, system, computingentity, entity, and/or similar words used herein interchangeably mayrefer to, for example, one or more computers, computing entities,desktops, mobile phones, tablets, phablets, notebooks, laptops,distributed systems, kiosks, input terminals, servers or servernetworks, blades, gateways, switches, processing devices, processingentities, set-top boxes, relays, routers, network access points, basestations, the like, and/or any combination of devices or entitiesadapted to perform the functions, operations, and/or processes describedherein. External computing entities 400 can be operated by variousparties. As shown in FIG. 4 , the external computing device 400 caninclude an antenna 408, a transmitter 409 (e.g., radio), a receiver 410(e.g., radio), and a processing element 402 (e.g., CPLDs,microprocessors, multi-core processors, coprocessing entities, ASIPs,microcontrollers, and/or controllers) that provides signals to andreceives signals from the transmitter 409 and receiver 410,correspondingly.

The signals provided to and received from the transmitter 409 and thereceiver 410, correspondingly, may include signaling information/data inaccordance with air interface standards of applicable wireless systems.In this regard, the external computing device 400 may be capable ofoperating with one or more air interface standards, communicationprotocols, modulation types, and access types. More particularly, theexternal computing device 400 may operate in accordance with any of anumber of wireless communication standards and protocols, such as thosedescribed above with regard to the computing device 30. In a particularembodiment, the external computing device 400 may operate in accordancewith multiple wireless communication standards and protocols, such asUMTS, CDMA2000, 1×RTT, WCDMA, GSM, EDGE, TD-SCDMA, LTE, E-UTRAN, EVDO,HSPA, HSDPA, Wi-Fi, Wi-Fi Direct, WiMAX, UWB, IR, NFC, Bluetooth, USB,and/or the like. Similarly, the external computing device 400 mayoperate in accordance with multiple wired communication standards andprotocols, such as those described above with regard to the computingdevice 30 via a network interface 406.

Via these communication standards and protocols, the external computingdevice 400 can communicate with various other entities using conceptssuch as Unstructured Supplementary Service Data (USSD), Short MessageService (SMS), Multimedia Messaging Service (MMS), Dual-ToneMulti-Frequency Signaling (DTMF), and/or Subscriber Identity ModuleDialer (SIM dialer). The external computing device 400 can also downloadchanges, add-ons, and updates, for instance, to its firmware, software(e.g., including executable instructions, applications, programmodules), and operating system.

According to one embodiment, the external computing device 400 mayinclude location determining aspects, devices, modules, functionalities,and/or similar words used herein interchangeably. For example, theexternal computing device 400 may include outdoor positioning aspects,such as a location module adapted to acquire, for example, latitude,longitude, altitude, geocode, course, direction, heading, speed,universal time (UTC), date, and/or various other information/data. Inone embodiment, the location module can acquire data, sometimes known asephemeris data, by identifying the number of satellites in view and therelative positions of those satellites (e.g., using global positioningsystems (GPS)). The satellites may be a variety of different satellites,including Low Earth Orbit (LEO) satellite systems, Department of Defense(DOD) satellite systems, the European Union Galileo positioning systems,the Chinese Compass navigation systems, Indian Regional Navigationalsatellite systems, and/or the like. This data can be collected using avariety of coordinate systems, such as the Decimal Degrees (DD);Degrees, Minutes, Seconds (DMS); Universal Transverse Mercator (UTM);Universal Polar Stereographic (UPS) coordinate systems; and/or the like.Alternatively, the location information/data can be determined bytriangulating the external computing entity's 400 position in connectionwith a variety of other systems, including cellular towers, Wi-Fi accesspoints, and/or the like. Similarly, the external computing device 400may include indoor positioning aspects, such as a location moduleadapted to acquire, for example, latitude, longitude, altitude, geocode,course, direction, heading, speed, time, date, and/or various otherinformation/data. Some of the indoor systems may use various position orlocation technologies including RFID tags, indoor beacons ortransmitters, Wi-Fi access points, cellular towers, nearby computingdevices (e.g., smartphones, laptops) and/or the like. For instance, suchtechnologies may include the iBeacons, Gimbal proximity beacons,Bluetooth Low Energy (BLE) transmitters, NFC transmitters, and/or thelike. These indoor positioning aspects can be used in a variety ofsettings to determine the location of someone or something to withininches or centimeters.

The external computing device 400 may also comprise a user interface(that can include a display 407 coupled to the processing element 402)and/or a user input interface (coupled to the processing element 402).For example, the user interface may be a user application, browser, userinterface, and/or similar words used herein interchangeably executing onand/or accessible via the external computing device 400 to interact withand/or cause display of information/data from the computing device 30,as described herein. The user input interface can comprise any of anumber of devices or interfaces allowing the external computing device400 to receive data, such as a keypad 411 (hard or soft), a touchdisplay, voice/speech or motion interfaces, or other input device. Inembodiments including a keypad 411, the keypad 411 can include (or causedisplay of) the conventional numeric (0-9) and related keys (#, *), andother keys used for operating the external computing device 400 and mayinclude a full set of alphabetic keys or set of keys that may beactivated to provide a full set of alphanumeric keys. In addition toproviding input, the user input interface can be used, for example, toactivate or deactivate certain functions, such as screen savers and/orsleep modes.

The external computing device 400 can also include volatile storage ormemory 404 and/or non-volatile storage or memory 403, which can beembedded and/or may be removable. For example, the non-volatile memorymay be ROM, PROM, EPROM, EEPROM, flash memory, MMCs, SD memory cards,Memory Sticks, CBRAM, PRAM, FeRAM, NVRAM, MRAM, RRAM, SONOS, FJG RAM,Millipede memory, racetrack memory, and/or the like. The volatile memorymay be RAM, DRAM, SRAM, FPM DRAM, EDO DRAM, SDRAM, DDR SDRAM, DDR2SDRAM, DDR3 SDRAM, RDRAM, TTRAM, T-RAM, Z-RAM, RIMM, DIMM, SIMM, VRAM,cache memory, register memory, and/or the like. The volatile andnon-volatile storage or memory can store databases, database instances,database management systems, data, applications, programs, programmodules, scripts, source code, object code, byte code, compiled code,interpreted code, machine code, executable instructions, and/or the liketo implement the functions of the external computing device 400. Asindicated, this may include a user application that is resident on theentity or accessible through a browser or other user interface forcommunicating with the computing entity 30 and/or various othercomputing entities.

In another embodiment, the external computing device 400 may include oneor more components or functionality that are the same or similar tothose of the computing device 30, as described in greater detail above.As will be recognized, these architectures and descriptions are providedfor exemplary purposes only and are not limiting to the variousembodiments.

In some embodiments, the apparatus 20 can comprise the computing device30, the computing device 30 suitable to carry out movement of thevarious components of the apparatus 20, flow rates ordeposition/dispersal volumes, or the like. In some embodiments, theapparatus 20 or a component thereof, e.g., the computing device 30, canbe configured to be in communication with the external computing device400, which can be configured to provide instructions for printing, adesign file for a printed article, printing nozzle and/or nebulizer pathinstructions, or the like to the computing device 30, which isconfigured to carry out printing.

Referring now to FIG. 5 , a method 50 for three-dimensional printing ofa polymer article can comprise forming a liquid build material, theliquid build material comprising a polymeric material in a solvent, at51. In some embodiments, the method 50 can further comprise disposingthe liquid build material into a volume of air, at 52.

In some embodiments, the dissolved polymeric material can be injected,spun, inserted, communicated, dropped, conveyed, or otherwise dispensedwithin the printing environment such that the coagulation agent canfacilitate at least partial coagulation of the ink and formation of theintermediate or finished article. Regardless of the particular manner inwhich the dissolved polymeric material is dispensed within the printingenvironment, the coagulation agent can cause sufficient coagulation ofthe printed ink by replacing the solvent in the ink and causing thedeposited, at least partially coagulated build material (resulting fromthe solvent-exchanged ink) to be self-supporting, e.g., oflayer-by-layer deposition. According to some embodiments, theintermediate article or finished article may be formed, according to thedescribed approaches, free of printed support structures. Such supportstructures are used extensively across the array of conventionaladditive manufacturing and 3D printing techniques and are often requiredto be trimmed away after formation of the intermediate or finishedarticle. By forming the intermediate article without printed supports,the methods described herein (e.g., the method 50) can eliminate thelabor-intensive, costly, and time-consuming process step of trimmingaway the printed support structures once the article is fully formed.

In some embodiments, the solvent can include at least one from amongdimethyl sulfoxide (DMSO), dimethylformamide (DMF), acetonitrile,ethanol, combinations thereof, and the like.

In some embodiments, the method 50 can further comprise spraying anebulized coagulation agent within a predetermined distance of thedisposed liquid build material to at least partially coagulate theliquid build material, thereby forming the article, at 53. As describedelsewhere herein, the nebulizing agent may comprise a non-solvent or anysuitable material which initiates or accelerates coagulation of thepolymer either by phase inversion, by solvent exchange with the disposedliquid build material, or by any other suitable mechanism.

In some embodiments, the method 50 can, optionally, further comprisedissolving the polymeric material in the solvent to form the liquidbuild material, at 54. In some embodiments, the polymeric material caninclude at least one from among thermoplastic polymer, thermosettingpolymers, acrylonitrile-butadiene-styrene, polyurethane, acrylic,poly(acrylonitrile), polyolefins, polyvinyl chlorides, nylons,fluorocarbons, polystyrenes, polyethylene, ultra-high molecular weightpolyethylene, polypropylene, polybutene, polymethylpentene,polyisoprene, copolymers thereof, and their combinations, mixturescontaining two or more of the following polyethylene, ultra-highmolecular weight polyethylene, and polypropylene, as well as, mixturesof the foregoing with copolymers such as ethylene-butene copolymers andethylene-hexene copolymers, thermosetting plastics, such as polyimide(PI), poly amide (PA), and poly amide imide (PAI), polypropylene (PP),polyethylene (PE), ethylene vinylacetate (EVA), poly(ethyleneterephthalate) (PET), poly-vinyl acetate (PVA), polyamide (PA), acrylicadhesives, ultraviolet (UV)/electron beam (EB)/infrared (IR) curableresin, polyether ether ketone (PEEK), polyethylene naphthalate (PEN),polyethersulfone (PES), polyphenylene sulfide (PPS), polyphenylene oxide(PPO), and any combinations thereof. In some embodiments, the solventfor dissolution of the polymeric material(s) can by any suitablesolvent, such as dimethylsulfoxide (DMSO), ethanol, N-methylpyrrolidone,cyclodextrin, a pluronic detergent, liposomes, acetonitrile,N,N-Dimethylformamide (DMF), sodium methyl sulfinylmethylide, dimethylsulfide, dimethyl sulfone, acetone, dimethylformamide,dimethylacetamide, N-methyl-2-pyrrolidone, HMPA, methanol, isopropanol,tert-butanol, acetic acid, ether, tetrahydrofuran, dichloromethane,chloroform, triethylamine, pyridine, ethyl acetate, variants thereof,combinations thereof, and/or the like.

Referring now to FIG. 6 , a method 60 for three-dimensional printing ofa polymer article can comprise disposing a first volume of a liquidbuild material onto a substrate, at 61. The method 60 can furthercomprise within a predetermined time following disposing the firstvolume of the liquid build material onto the substrate, spraying a firstvolume of a nebulized coagulation agent within a predetermined distanceof the disposed first volume of the liquid build material to at leastpartially coagulate the first volume of the first volume of the liquidbuild material, at 62. The method 60 can further comprise disposing asecond volume of the liquid build material onto at least a portion ofthe at least partially coagulated first volume of the liquid buildmaterial, at 63. The method 60 can further comprise within thepredetermined time following disposing the second volume of the liquidbuild material onto at least the portion of the at least partiallycoagulated first volume of the liquid build material, spraying a secondvolume of the nebulized coagulation agent within the predetermineddistance of the disposed second volume of the liquid build material toat least partially coagulate the second volume of the liquid buildmaterial, at 64.

In some embodiments, spraying the first volume and the second volume ofthe nebulized coagulation agent within the predetermined distance of thedisposed first and second volumes of the liquid build material onlypartially coagulates the liquid build material, the method 60 canfurther comprise: exposing the article to a post-printing coagulationsolution to fully solidify the article. In some embodiments, exposingthe article to the post-printing coagulation solution comprisessubmerging the article in a bath of the post-printing coagulationsolution. In some embodiments, the liquid build material comprises atleast one polymeric material and at least one solvent. In someembodiments, the method 60 can be carried out by an apparatus comprisingone or more reservoirs configured to contain a supply of the liquidbuild material, a nozzle, and a computing device. In some embodiments,the nozzle is configured and dimensioned to move along a predeterminedpath within the volume of air to dispose a volume of the liquid buildmaterial. In some embodiments, the predetermined path is determined bythe computing device based upon an input design file comprising a designof the finished article. In some embodiments, the apparatus can beconfigured to communicate the liquid build material from the reservoir,through the nozzle, and into the volume of air.

Referring now to FIG. 7 , a method 70 for three-dimensional printing ofa polymer article can comprise forming a liquid build material, theliquid build material comprising a polymeric material in a solvent, at71. The method 70 can further comprise disposing the liquid buildmaterial into a volume of air, at 72. The method 70 can further comprisespraying a nebulized coagulation agent within a predetermined distanceof the disposed liquid build material to at least partially coagulatethe liquid build material, thereby forming the article, at 73. Themethod 70 can, optionally, further comprise exposing the intermediatearticle to a post-printing coagulation solution to fully solidify theintermediate article, forming the finished article, at 74. The method 70can, optionally, further comprise dissolving the polymeric material inthe solvent to form the liquid build material, at 75.

In some embodiments, spraying the nebulized coagulation agent within thepredetermined distance of the disposed liquid build material is donewithin a predetermined time following the disposing the liquid buildmaterial into the volume of air. In some embodiments, spraying thenebulized coagulation agent within the predetermined distance of thedisposed liquid build material within the predetermined time followingthe disposing the liquid build material into the volume of air onlypartially coagulates the liquid build material, the method 70 canfurther comprise: exposing the intermediate article to a post-printingcoagulation solution to fully solidify the intermediate article, formingthe finished article. In some embodiments, exposing the intermediatearticle to the post-printing coagulation solution comprises submergingthe intermediate article in a bath of the post-printing coagulationsolution. In some embodiments, the method 70 further comprisesdissolving the polymeric material in the solvent to form the liquidbuild material. In some embodiments, at least one of the forming, thedisposing, the spraying, or the exposing is carried out by an apparatus(e.g., the apparatus 20) comprising one or more reservoirs configured tocontain a supply of the liquid build material, a nozzle, and a computingdevice (e.g., the computing device 30, the external computing device400, etc.). In some embodiments, the nozzle is configured anddimensioned to move along a predetermined path within the volume of airto dispose a volume of the liquid build material. In some embodiments,the predetermined path is determined by the computing device based uponan input design file comprising a design of the finished article. Insome embodiments, the apparatus is configured to communicate the liquidbuild material from the reservoir, through the nozzle, and into thevolume of air. In some embodiments, the intermediate article is formedfree of printed support structures.

In some embodiments, the build material can comprise any suitablepolymeric material such as a thermoplastic. In some embodiments, apolymeric material can be dissolved or dispersed in any suitablesolvent. In some embodiments, such a solvent can comprise dimethylsulfoxide (DMSO), and/or the like. In some embodiments, to form thebuild material, the polymeric material can be dissolved in the solventpartially or fully, at about room temperature (about 20° C. to about 25°C.), or at an elevated temperature, while being stirred, shaken,agitated, bombarded with electromagnetic radiation and/or ultrasonicsound waves, or the like. In some embodiments, one or more solvents canbe chosen that are capable of breaking down the build material withoutcausing molecular degradation or a reduction in the degree ofpolymerization (DP). Conventional additive manufacturing and 3D printingtechniques for polymeric materials typically requires melting thepolymeric material at least partially if not fully to facilitate thecommunication and build-up of the article using the polymeric material.These conventional additive manufacturing and 3D printing techniques forpolymeric materials can require high heat, which can make the processcostly, dangerous, time-consuming, and limiting in terms of thereusability of printing materials. By contrast, the room temperatureprocess according to some embodiments described herein requires noheating of the printing materials, no thermal deterioration of thepolymers, and can eliminate the process step from conventional additivemanufacturing and 3D printing methods of heating and/or melting thepolymeric material.

In some embodiments, the post-printing solidification bath can compriseany suitable material with regard to the 3D printing material (e.g., thebuild material) and/or the solvent chosen, for instance one or more ofwater, deionized water, ethanol, and the like. Many other compositionsand concentrations of post-printing coagulation solution were tested,are contemplated, and are within the scope of the current disclosure.

In some embodiments, the polymeric material can be dissolved ordispersed in any suitable solvent, such as but not limited to dimethylsulfoxide (DMSO), and the like. The polymeric material can be dissolvedor dispersed in the solvent partially or fully, at about roomtemperature (about 20° C. to about 25° C.). Alternatively, the polymericmaterial can be dissolved or dispersed at a temperature less than orgreater than about room temperature. In some embodiments, dissolution ofthe polymer material for 3D printing can be accomplished with the helpof other processes or energies, such as by stirring, shaking oragitating the polymeric material/solvent mixture, by bombarding themixture with ultrasonic waves, electromagnetic energy, or otherenergies, and/or the like. The solvent or solvents can be chosen suchthat the solvent can break down the build material without causingmolecular degradation or a reduction in the degree of polymerization(DP). Conventional additive manufacturing and 3D printing techniques forpolymeric materials typically requires melting the polymeric material atleast partially if not fully to facilitate the communication andbuild-up of the article using the polymeric material. These conventionaladditive manufacturing and 3D printing techniques for polymericmaterials can require high heat to melt the build material, which canmake the conventional processes costly, relatively more dangerous,time-consuming, and/or limiting in terms of the reusability of printingmaterials. By contrast, the methods 50, 60, 70 described herein,according to some embodiments, can be carried out at or around roomtemperature and therefore do not require heat to be applied during theprocess, do not induce thermal deterioration of the polymers, and mayeliminate the process steps of heating and/or melting the polymericmaterial.

Select Experimental Results

Referring now to FIG. 8 , an exemplary process 80 is provided forsolvent-assisted 3D printing of a build material (e.g., “ink”) in air atambient temperature and pressure, without requiring melting of thepolymer in the build material, without requiring any concurrentlyprinted supports, and without requiring the use of a liquid orsemi-solid support bath material during printing.

According to some embodiments, the ink can be prepared by mixing about50% (v/v) of a solvent, e.g., DMSO (Bioreagent grade, Fisher, Fair Lawn,N.J., USA) with about 50% (w/v) of a polymeric material, e.g., ABS(ABSplus P430, Stratasys, Eden Prairie, Mich., USA) (FIG. 8 , element(a). The mixture can be warmed up to about 80° C. and continuouslystirred (FIG. 8 , element (b)) to ensure faster dissolution, e.g., usinga roller mixer (DLAB Scientific, Riverside, Calif., USA) to enhancehomogeneity within the mixture. The ink can then be loaded in adisposable 5 mL syringe fitted with a stainless steel 23-gauge tip(Nordson EFD, Vilters, Switzerland). The syringe can then be assembledonto a Hyrel Engine SR (Hyrel3D, Norcross, Ga., USA) with a CSD-5dispensing head (ultraviolet array not used). In some embodiments,G-code files can be obtained by slicing STL models using the embeddedSlic3r utility in Hyrel's Repetrel software. Some parameters that can beused are: layer thickness 0.15 mm and speed 60-120 mm/min. Whileprinting, a deionized water mist can be supplied simultaneously as acoagulant (FIG. 8 , element (c)) using a nebulizer (Lumiscope, EastRutherford, N.J., USA) in order to induce at least partial coagulationonto the structure being printed. In some embodiments, an enclosedchamber can be used to control the printing environment. The 3D printedpart can then be immersed in water, e.g., 100 mL of water for 1 hour, toenhance the replacement of the solvent (e.g., DMSO) withcoagulant/non-solvent (e.g., water) and therefore fully coagulate theprinted polymer part (FIG. 8 , element (d)). In some embodiments, thepost-printing coagulation/solidification bath may not be needed, but inother embodiments it may be used to fully facilitate thenon-solvent—solvent exchange and fully solidify the printed article. Insome embodiments, the printed part can then be dried, e.g., at roomtemperature (FIG. 8 , element (e1)), and the process-induced solvent canbe reclaimed, e.g., through a distillation process (FIG. 8 , element(e2)).

Exemplary Printed Articles

One or more of the described processes 10, 80, or methods 50, 60, 70(including parts or variations thereof) can be carried out for thefabrication of arbitrary parts in arbitrary orientations. In otherwords, the complexity, costliness, and time necessary to carry outfabrication is at least partially decoupled from the shape, dimensions,and complexity of the article being fabricated. The implications forpractical applications are surprising and significant. Conversely, 3Dprinting a polymeric article, e.g., an article having high complexity,according to conventional processes requires a not insignificant amountof thought, time, and/or computing power be dedicated to the printingorientation of the part to maximize printing precision and minimizeprinting time, requires careful placement of printed support structuressuch that the printed article is sufficiently stabilized and such thatthe printed support structures are minimized, and requires time, labor,and therefore cost to trim away the support structures from the finishedarticle, a process which sometimes damages the printed article such thatthe printed article must be scrapped. The 3D printing methods, e.g., themethods 50, 60, 70, described herein can eliminate the need for aparticular orientation, are not rendered more time-consuming or costlywith increasing article complexity, and do not require supportstructures to be printed concurrent to the printing of the article,meaning less 3D printing/build material is wasted and the printedsupport structure trimming step is eliminated completely. The advantagesin terms of production cost and time for 3D printed articles, amongother advantages associated with these methods, are clear.

By way of example only, exemplary printed articles are illustrated inFIG. 9 . For instance, a printing sequence is illustrated in FIG. 9 , inphotographs a) through g), that captures the printing process at variouspoints during the printing process, for a thin-walled ABS vase.Likewise, photo h) of FIG. 9 illustrates a bulky ABS article printedaccording to one of the disclosed solvent-assisted 3D printing in airmethods or approaches. In FIG. 9 , the inset white scale bars in photoa) and photo h) both illustrate 10 mm with respect to the scale of theprinted articles.

In general, the printed parts closely match the original design,regardless of the build material. For each material, ink polymer/solventconcentrations, coagulant choice and concentration, post-printingsolidification bath materials, and print parameters were optimized forbest results; material details are discussed in more detail elsewhereherein. Wall thickness of, for example, the printed vase of FIG. 9 ,photos a)-g), was on the order of between about 100 μm and about 500 μm,inclusive of all values and ranges therebetween. In some embodiments,the wall thickness of a hollow printed article and/or other dimensionscan be reduced by reducing the size or bore of the printing nozzle.

As illustrated, printed ABS structures demonstrate a variety of featuretypes: thin walls, flat overhangs, solid regions, and detailed surfaces.The gear vase and tubular structures illustrate the ability to printfunctional containers and conduits with arbitrary features otherwiseunachievable by additive manufacturing such as the perfectly horizontalupper section of the T-junction. Attempting to form structures having asimilar form factor using FDM would require a more complex printingprocess and would result in a formed article that is mechanically andstructurally deficient. For instance, to print structures having asimilar form factor using FDM would require the part and/or the entireprinting platform be rotated in space during printing, resulting in amore complex printing process, requiring more complex parts sinceanalogous features may not have an “easy” orientation for 3D printingaccording to FDM. In contrast, using a direct printing in air approachin conjunction with a misted or nebulized coagulant, according to any ofthe embodiments described herein, the print quality is nearlyindependent of orientation of the printed article and results in moreaccurate and precise printing of the article relative to the inputmodel. Also, the thin walls of a printed tube or vase, which oftentimesdeform during or after FDM printing, were substantially unaffected bygravity during the disclosed solvent-enabled direct freeform printing inair approach, which may be due to the fact that at least a part, e.g., asurface portion, of the deposited ink coagulates in the presence of thenebulized or aerosolized or misted coagulant, meaning that the strain ofgravity and other factors on the intermediate article during printingdoes not cause deformation or strain of the intermediate article.

By way of example only, since the coagulation of the printed materialoften requires diffusion of the dispersed (e.g., nebulized) coagulationagent into the ink, thin walled parts or shells such as the hollow vasestructures are sometimes more convenient to print using the describedprocesses than according to any conventional process. Furthermore, insome embodiments, such as illustrated in FIG. 9 , photo h), bulk solidparts are also achievable using the described approaches. Blocks havingdimensions of, for instance, 8×8×6 mm were printed as a test case todetermine parameters and verify that they can be fabricated, howeverother bulk and solid parts and structures were also successfullyprinted, and many others were contemplated and are covered by thepresent disclosure. The coagulation process for material within the bulkpart is complicated by the presence of the coagulated shell around theexterior. This prevents shrinkage of the overall shape as solvent slowlydiffuses out of the interior leaving behind coagulated solid buildmaterial. In some cases, the volumetric shrinkage is accommodated by theformation of void space within the bulk part, as discussed in moredetail in the following section. A more controllable option is to reducethe print speed so that the interior layers almost completely coagulateas the next layer is being printed. This ensures that the entire volumeof the printed part experiences similar coagulation conditions andminimizes the occurrence of voids in printed parts.

As described herein, processes, approaches, methods, apparatuses,systems, computer program products, and the like are described forpolymer 3D printing of dissolved polymer into air to form an article orother structure, while a coagulation agent is delivered, e.g., innebulized form, to at least partially solidify printed features. Withoutwishing to be bound by any particular theory, the at least partialsolidification caused by nebulized coagulation agent, may be caused by aphase inversion mechanism. In some embodiments, delivering a nebulizedcoagulation agent before, during, and/or after deposition, injection, orprinting of the build material may enhance the self-supporting propertyof the printed part as the phase inversion process begins and/or iscarried out. As a result, polymer structures can be printed in air atroom temperature without the need to melt the polymer or inject/printthe melted polymer in layers and at a pace suitable for cooling of thedeposited melted polymer layers. According to some embodiments, apost-printing process, if needed, can include fully solidifying theprinted part by immersing it in a post-printing solidification bath toinduce a complete solvent-non-solvent exchange, and reclaiming residualsolvent for the printing chamber and post-printing solidification bath.The described polymer printing approach was experimentally shown to workusing DMSO as a solvent, ABS as a build polymer, and a water mist as acoagulation agent during, before, and/or immediately after printing,which enabled the printed polymer structures to be printed at ambienttemperature and pressure and to self-supporting without requiringconcurrently printed support structures or a yield-stress support bath.

According to some embodiments, the methods disclosed herein are capableof freeform printing using materials such as acrylonitrile butadienestyrene (ABS), polyurethane (PU), polyacrylonitrile (PAN, also known aspolyvinyl cyanide), acrylics, and/or other suitable materials, to formfinished articles having wide ranges of dimensions, complexity, andprinting precision. By way of example only, complex and precise articlessuch as a spiral cone can be printed according to embodiments of themethod described herein, the precise article having a singular supportat the top of the spiral cone from which the arms of the spiral coneextend rotationally. According to some embodiments, the methods, e.g.,the method 10, disclosed herein typically result in superior articleproperties and result in the realization of certain efficiencies duringprinting associated with only printing the article and not printingsupport structures. Furthermore, there are efficiencies ofpost-processing associated with not having to remove (trim) supportstructures from the 3D printed article. Also, the coagulation agentand/or post-printing solidification bath (or portions thereof) may bereusable for subsequent printing or solidification of another article,which may mean that, unlike conventional 3D printing platforms whichmust be cleaned and any excess printing medium or build material removedbefore subsequent printing within or on the same 3D printing platform,the disclosed methods, apparatuses, systems, and materials enable therapid reuse of the 3D printing platform and the rapid completion of afinished article without requiring, for instance, the removal of supportstructures from the printed article.

In some embodiments, a polymer 3D printing method is illustrated that isconfigured to enable freeform fabrication of polymeric structures underambient conditions without the use of printed support structures. Insome embodiments, the method can include injecting a thermoplasticpolymer and solvent solution into an air-filled printing environment.The injecting can be carried out by any suitable mechanical apparatussuch as a syringe, plunger, nozzle, pipe, conduit, pathway, or the like.In some embodiments, the build material, can be previously dissolved orcaused to be dissolved in a suitable solvent to make a viscous polymersolution, which can be loaded into an ink reservoir for extrusionprinting as part of the injecting. The polymer solution, during theinjecting, can be directly printed in (injected into) the open air ofthe printing environment, and can be supported initially on a substrateat the bottom of the printing environment and then can be self-supportedon earlier/lower portions of the 3D printed article that were alreadyprinted and at least partially coagulated or at least partiallysolidified.

In some embodiments, the printing nozzle or other mechanical apparatusconfigured to inject or extrude the build material into the printingenvironment can be fixed or configured to be moved during the injecting.For instance, in some embodiments, a computing device, e.g., a computerincluding at least one processor and at least one memory device, can beconfigured to move or cause movement of the printing nozzle betweendifferent locations or portions of the printing environment, e.g.,printing enclosure. In some embodiments, the computing device can moveor cause movement of the printing nozzle along a computer-controlledpath or paths while injecting to form filaments, layers, and eventuallyan entire 3D part in the printing environment.

Likewise, a nozzle, such as a spray nozzle, nebulizer nozzle, or thelike may be used to deliver a volume of the coagulation agent to theprinting environment.

In some embodiments, after introducing the coagulation agent, theprinted part may be only partially coagulated for some time afterinjecting or may remain only partially coagulated for an extended periodof time after injecting. Partial coagulation may effectively preventexcessive deformation of the printed ink such that the full intermediatearticle can be formed without a loss of form factor or dimensionsrelative to the desired form factor and dimensions of the printedarticle between the time that the intermediate article is printed andthe time that full coagulation/solidification takes place. In someembodiments, one of the important functions of the one or more solventsin the build material (ink) may be to dissolve or otherwise comingle oneor more polymeric materials with the one or more solvents and to preventunwanted, early coagulation of polymers in the build material before thebuild material is properly printed into the printing environment. Insome embodiments, a non-solvent such as the coagulation agent or acomponent thereof may be delivered to nearby (e.g., within apredetermined distance of) the printed build material to initiate the(at least partial) coagulation process. Thus, the type of solvent andnon-solvent chosen, as well as the ratio of solvent in the buildmaterial to non-solvent in the coagulation agent can be finely tuned, inlight of the material choices and ratio of polymeric build material andsolvent in the printing solution, to achieve the desired degree ofcoagulation for an intermediate article or a finished article.

In some embodiments in which the coagulation agent produces an onlypartially coagulated build material, thereby forming the intermediatearticle, the method can further include exposing the intermediatearticle to a post-printing solidification bath, e.g., by immersing theintermediate article in the post-printing solidification bath, tosolidify the intermediate article and thereby form the finished article,a fully solidified 3D printed polymer part or bulk object. Aftersufficient time and/or once the finished article is formed in terms ofthe degree of coagulation/solidification of the article, the finishedarticle can then be removed from the post-printing solidification bath.In some embodiments, no further steps or processes or treatments arerequired after removal of the finished article the post-printingsolidification bath in order to achieve a finished article having thedesired dimensions and mechanical properties of the finished printedpart.

In some embodiments, it may be helpful for a structure being printed toremain partially liquid (to be only partially coagulated) to avoidfilament/layer interfaces and nozzle clogging. The printing of apartially liquid structure can be accomplished using the nebulized orotherwise dispersed coagulation agent or non-solvent before, during,and/or immediately after printing of the build material into theprinting environment.

In some embodiments, once the ink (e.g., solvent solution comprisingfluid build material) is injected, dispensed into, extruded, and/orotherwise disposed within the printing environment and exposed to thecoagulation agent dispersed nearby the point of printing of the buildmaterial, the ink (e.g., comprising the fluid build material) is then atleast partially coagulated and trapped in the particular desiredlocation within the printing environment as the printing nozzle travelsaway from the particular location at which the ink is deposited. In someembodiments, the build material is then trapped in a 3D configurationdefined by a travel path defined for the printing nozzle and may retainits shape even though it is still partially fluid. In some embodiments,the dispersed coagulation agent may coagulate or cause solidification ofonly a surface or a surface portion of the deposited ink, which may meanthat a portion of the printed ink within the solidified portion orpartially solidified portion of the deposited ink may remain partiallyor fully liquid. An entire 3D fluid intermediate part can be formed inthis way. Then, a stimulus can be applied which causes or contributes tofull or solidification or partial solidification of the at leastpartially fluid (only partially coagulated) build material so that itcan be removed from the printing environment as an intact part andexposed to or immersed in the post-printing solidification bath. In someembodiments, the intermediate part can be exposed to the post-printingsolidification bath or a further coagulation solution, which may besimilar to or different from the dispersed coagulation agent in terms ofmaterial(s) used phase(s); while in other embodiments the coagulationsolution or the like can be introduced to the printing environmentwithout first moving the intermediate article out of the printingenvironment, thereby exposing the intermediate article to thecoagulation solution or the like.

CONCLUSIONS

A polymer three-dimensional (3D) printing method and associatedapparatus are disclosed for fabrication of 3D printed structures andarticles. In some embodiments, the fabrication may be freeformfabrication. In some embodiments, the 3D printed structures and articlesmay be formed from a build material, such as a polymeric material withthe assistance of a solvent or a polymer/solvent solution.

In some embodiments, 3D printed structures and articles may befabricated under ambient conditions and/or without the use of printedsupport structures which would need to be removed after 3D printing inorder to achieve the finished structure or article. In some embodiments,a build material can be dissolved in a suitable solvent or solventsolution (e.g., solvent/non-solvent mixture) such that the resultingsolution is a suitable ink for 3D printing. In some embodiments, thebuild material can comprise one or more polymers or a polymer solution.In some embodiments, the ink, comprising the build material, can bedisposed within a printing volume or onto a printing platform withoutthe use of supports or other structures being previously, concurrently,or subsequently printed to support the build material while the buildmaterial solidifies. In some embodiments, freeform printing can becarried out at ambient temperature and pressure. In some embodiments,just previous to, concurrent with, or just following the disposition ofink into the printing volume or onto the printing platform, a volume ofa coagulation agent, such as a coagulant, a non-solvent, variationsthereof, or combinations thereof, can be disposed, such as by an aerosolsprayer or other suitable dispensing mechanism, to a volume directlyadjacent the disposed ink. Without wishing to be bound by any particulartheory, the coagulation agent can cause partial, substantially complete,or complete coagulation, solidification, polymerization, phaseinversion, cross-linking, crystallization, calcification, concretion,setting, stiffening, hardening, amalgamation, strengthening, gelation,congealing, thickening, densification, annealing, shaping, forming,clotting, variations thereof, combinations thereof, or the like. Assuch, a first volume of ink can be printed, e.g., by a nozzle or thelike, in a freeform manner directly into air and partially or fullysolidified by disposing a first volume of the coagulation agentsufficiently close by the printed ink, the nozzle can move a distance,in a particular direction, from the previous printing location and printa second volume of ink, e.g., adjacent the first volume of ink (nowpartially or fully solidified), dispose a second volume of thecoagulation agent to partially or fully solidify the second volume ofink, and continue along a predetermined path through the printing volumeor across the printing platform in order to completely print anintermediate or finished article without being required to melt thebuild material, without requiring use of support structures, and/orwithout requiring use of a support bath or the like to maintain thestructure of the printed article prior to completion of printing of thearticle. In some embodiments, an intermediate article may be one inwhich some or all of the article is only partially solidified or forwhich further processing is helpful or required to achieve the finishedarticle.

In some embodiments, if an intermediate article is formed, heat, achemical reactant, electromagnetic radiation, and/or the like may beused to fully solidify or otherwise process the intermediate article toform the finished article.

In some embodiments, a method for three-dimensional printing of aprinted article can comprise forming a liquid build material, the liquidbuild material comprising a polymeric material in a solvent; disposingthe liquid build material into a volume of air; and spraying a nebulizedcoagulation agent within a predetermined distance of the disposed liquidbuild material to at least partially coagulate the liquid buildmaterial, thereby forming the article. In some embodiments, spraying thenebulized coagulation agent within the predetermined distance of thedisposed liquid build material is done within a predetermined timefollowing the disposing the liquid build material into the volume ofair. In some embodiments, spraying the nebulized coagulation agentwithin the predetermined distance of the disposed liquid build materialwithin the predetermined time following the disposing the liquid buildmaterial into the volume of air only partially coagulates the liquidbuild material, the method further comprising: exposing the intermediatearticle to a post-printing coagulation solution to fully solidify theintermediate article, forming the finished article. In some embodiments,exposing the intermediate article to the post-printing coagulationsolution comprises submerging the intermediate article in a bath of thepost-printing coagulation solution. In some embodiments, the methodfurther comprises dissolving the polymeric material in the solvent toform the liquid build material. In some embodiments, at least one of theforming, the disposing, the spraying, or the exposing is carried out byan apparatus comprising one or more reservoirs configured to contain asupply of the liquid build material, a nozzle, and a computing device.In some embodiments, the nozzle is configured and dimensioned to movealong a predetermined path within the volume of air to dispose a volumeof the liquid build material. In some embodiments, the predeterminedpath is determined by the computing device based upon an input designfile comprising a design of the finished article. In some embodiments,the apparatus is configured to communicate the liquid build materialfrom the reservoir, through the nozzle, and into the volume of air. Insome embodiments, the intermediate article is formed free of printedsupport structures.

In some embodiments, the method can further comprise, optionally,dissolving a polymeric material in a solvent to form the build material(e.g., “the liquid build material,” “the ink,” or “the polymericsolution”). In some embodiments, the build material can comprise anysuitable polymeric material such as a thermoplastic. In someembodiments, a polymeric material can be dissolved or dispersed in anysuitable solvent. In some embodiments, such a solvent can comprisedimethyl sulfoxide (DMSO), and/or the like. In some embodiments, to formthe build material, the polymeric material can be dissolved in thesolvent partially or fully, at about room temperature (about 20° C. toabout 25° C.), or at an elevated temperature, while being stirred,shaken, agitated, bombarded with electromagnetic radiation and/orultrasonic sound waves, or the like. In some embodiments, one or moresolvents can be chosen that are capable of breaking down the buildmaterial without causing molecular degradation or a reduction in thedegree of polymerization (DP). Conventional additive manufacturing and3D printing techniques for polymeric materials typically requiresmelting the polymeric material at least partially if not fully tofacilitate the communication and build-up of the article using thepolymeric material. These conventional additive manufacturing and 3Dprinting techniques for polymeric materials can require high heat, whichcan make the process costly, dangerous, time-consuming, and limiting interms of the reusability of printing materials. By contrast, the roomtemperature process according to some embodiments described hereinrequires no heating of the printing materials, no thermal deteriorationof the polymers, and can eliminate the process step from conventionaladditive manufacturing and 3D printing methods of heating and/or meltingthe polymeric material.

According to another embodiment, a method can be provided for 3Dprinting an article that comprises: disposing a first volume of a liquidbuild material onto a substrate; within a predetermined time followingdisposing the first volume of the liquid build material onto thesubstrate, spraying a first volume of a nebulized coagulation agentwithin a predetermined distance of the disposed first volume of theliquid build material to at least partially coagulate the first volumeof the first volume of the liquid build material; disposing a secondvolume of the liquid build material onto at least a portion of the atleast partially coagulated first volume of the liquid build material;and within the predetermined time following disposing the second volumeof the liquid build material onto at least the portion of the at leastpartially coagulated first volume of the liquid build material, sprayinga second volume of the nebulized coagulation agent within thepredetermined distance of the disposed second volume of the liquid buildmaterial to at least partially coagulate the second volume of the liquidbuild material. In some embodiments, spraying the first volume and thesecond volume of the nebulized coagulation agent within thepredetermined distance of the disposed first and second volumes of theliquid build material only partially coagulates the liquid buildmaterial, the method further comprising: exposing the article to apost-printing coagulation solution to fully solidify the article. Insome embodiments, exposing the article to the post-printing coagulationsolution comprises submerging the article in a post-printingsolidification bath of the post-printing coagulation solution. In someembodiments, the liquid build material comprises at least one polymericmaterial and at least one solvent. In some embodiments, the method canbe carried out by an apparatus comprising one or more reservoirsconfigured to contain a supply of the liquid build material, a nozzle,and a computing device. In some embodiments, the nozzle is configuredand dimensioned to move along a predetermined path within the volume ofair to dispose a volume of the liquid build material. In someembodiments, the predetermined path is determined by the computingdevice based upon an input design file comprising a design of thefinished article. In some embodiments, the apparatus can be configuredto communicate the liquid build material from the reservoir, through thenozzle, and into the volume of air.

As such, according to another embodiment, an apparatus can be providedfor 3D printing a finished article. In some embodiments, the apparatuscan comprise: a printing space comprising an air-filled inner volume anda printing substrate; a reservoir configured to contain a supply of aliquid build material; a nozzle coupled to the reservoir and configuredto dispose a volume of the liquid build material into the air-filledinner volume of the printing space; a nebulizer configured to nebulize acoagulation agent and disperse the nebulized coagulation agent within apredetermined distance of the disposed volume of liquid build materialto at least partially coagulate the disposed volume of liquid buildmaterial; and a computing device configured to control movement of thenozzle and the disposing of the volume of the liquid build material intothe air-filled inner volume of the printing space. In some embodiments,the nebulized coagulation agent may only partially coagulate thedisposed volume of liquid build material to form an intermediatearticle. As such, in some embodiments, the apparatus can furthercomprise, optionally, a post-printing solidification bath comprising acoagulation fluid, the post-printing solidification bath configured toreceive the intermediate article, the coagulation fluid operable tofully solidify the article, if needed, thereby forming the finishedarticle.

In some embodiments, the build material can comprise a polymericmaterial, such as at least one from among thermoplastic polymer,thermosetting polymers, acrylonitrile-butadiene-styrene, polyurethane,acrylic, poly(acrylonitrile), polyolefins, polyvinyl chlorides, nylons,fluorocarbons, polystyrenes, polyethylene, ultra-high molecular weightpolyethylene, polypropylene, polybutene, polymethylpentene,polyisoprene, copolymers thereof, and their combinations, mixturescontaining two or more of the following polyethylene, ultra-highmolecular weight polyethylene, and polypropylene, as well as, mixturesof the foregoing with copolymers such as ethylene-butene copolymers andethylene-hexene copolymers, thermosetting plastics, such as polyimide(PI), poly amide (PA), and poly amide imide (PAI), polypropylene (PP),polyethylene (PE), ethylene vinylacetate (EVA), poly(ethyleneterephthalate) (PET), poly(vinyl acetate) (PVA), polyamide (PA), acrylicadhesives, ultraviolet (UV)/electron beam (EB)/infrared (IR) curableresin, polyether ether ketone (PEEK), polyethylene naphthalate (PEN),polyethersulfone (PES), polyphenylene sulfide (PPS), polyphenylene oxide(PPO), combinations thereof, and/or the like.

In some embodiments, the solvent can comprise at least one from amongdimethyl sulfoxide (DMSO), dimethylformamide (DMF), acetonitrile,ethanol, combinations thereof, and/or the like.

In some embodiments, such as when the nebulized coagulation agent onlypartially coagulates the liquid build material to form an intermediatepart, the intermediate part can be immersed, submerged, dipped, sprayedwith, coated with, or otherwise exposed to a coagulation solution tofully solidify the intermediate part into the finished article. Thecoagulation solution can comprise any suitable material, for instanceone or more of water, deionized water, ethanol, or the like.

It should be appreciated that all combinations of the foregoing conceptsand additional concepts discussed in greater detail below (provided suchconcepts are not mutually inconsistent) are contemplated as being partof the inventive subject matter disclosed herein. In particular, thecombinations of claimed subject matter appearing at the end of thisdisclosure are contemplated as being part of the inventive subjectmatter disclosed herein. It should be appreciated that terminologyexplicitly employed herein that also may appear in any disclosureincorporated by reference should be accorded a meaning consistent withthe particular concepts disclosed herein.

In some embodiments, one or more of the operations, steps, elements, orprocesses described herein may be modified or further amplified asdescribed below. Moreover, in some embodiments, additional optionaloperations may also be included. It should be appreciated that each ofthe modifications, optional additions, and/or amplifications describedherein may be included with the operations previously described herein,either alone or in combination, with any others from among the featuresdescribed herein.

The provided method description, illustrations, and process flowdiagrams are provided merely as illustrative examples and are notintended to require or imply that the steps of the various embodimentsmust each or all be performed and/or should be performed in the orderpresented or described. As will be appreciated by one of skill in theart, the order of steps in some or all of the embodiments described maybe performed in any order. Words such as “thereafter,” “then,” “next,”etc. are not intended to limit the order of the steps; these words aresimply used to guide the reader through the description of the methods.Further, any reference to claim elements in the singular, for example,using the articles “a,” “an,” or “the” is not to be construed aslimiting the element to the singular. Further, any reference todispensing, disposing, depositing, dispersing, conveying, injecting,inserting, communicating, and other such terms of art are not to beconstrued as limiting the element to any particular means or method orapparatus or system, and is taken to mean conveying the material withinthe receiving vessel, solution, conduit, or the like by way of anysuitable method.

Many modifications and other embodiments of the inventions set forthherein will come to mind to one skilled in the art to which theseinventions pertain having the benefit of teachings presented in theforegoing descriptions and the associated drawings. Although the figuresonly show certain components of the apparatus and systems describedherein, it is understood that various other components may be used inconjunction with the system. Therefore, it is to be understood that theinventions are not to be limited to the specific embodiments disclosedand that modifications and other embodiments are intended to be includedwithin the scope of the appended claims. Moreover, the steps in themethod described above may not necessarily occur in the order depictedin the accompanying diagrams, and in some cases one or more of the stepsdepicted may occur substantially simultaneously, or additional steps maybe involved. Although specific terms are employed herein, they are usedin a generic and descriptive sense only and not for purposes oflimitation. Specific equipment and materials described in the examplesare for illustration only and not for purposes of limitation. Forinstance, any and all articles, portions of articles, structures, bulkmaterials, and/or the like, having any form factor, scale, dimensions,aesthetic attributes, material properties, internal structures, and/ormechanical properties, which are formed according to any of thedisclosed methods, approaches, processes, or variations thereof, usingany devices, equipment, apparatuses, systems, or variations thereof,using any of the build material, printing mixture, ink, yield-stresssupport material, or other material compositions described herein orvariations thereof, are all contemplated and covered by the presentdisclosure. None of the examples provided are intended to, nor shouldthey, limit in any way the scope of the present disclosure.

Every document cited or referenced herein, including any crossreferenced or related patent or application is hereby incorporatedherein by reference in its entirety unless expressly excluded orotherwise limited. The citation of any document and/or the mention ofmethods or apparatuses as being conventional, typical, usual, or thelike is not, and should not be taken as an acknowledgement or any formof suggestion that the reference or mentioned method/apparatus is priorart with respect to any invention disclosed or claimed herein or that italone, or in any combination with any other reference or references,teaches, suggests or discloses any such invention or forms part of thecommon general knowledge in any country in the world. Further, to theextent that any meaning or definition of a term in this documentconflicts with any meaning or definition of the same term in a documentincorporated by reference, the meaning or definition assigned to thatterm in this document shall govern.

The various portions of the present disclosure, such as the Background,Summary, Brief Description of the Drawings, and Abstract sections, areprovided to comply with requirements of the MPEP and are not to beconsidered an admission of prior art or a suggestion that any portion orpart of the disclosure constitutes common general knowledge in anycountry in the world. The present disclosure is provided as a discussionof the inventor's own work and improvements based on the inventor's ownwork. See, e.g., Riverwood Intl Corp. v. R. A. Jones & Co., 324 F.3d1346, 1354 (Fed. Cir. 2003).

The invention claimed is:
 1. An apparatus for three-dimensional printingof a finished article, the apparatus comprising: a printing spacecomprising an air-filled inner volume and a printing substrate; areservoir configured to contain a supply of a liquid build material, theliquid build material comprising a polymer dissolved in a solvent; anozzle coupled to the reservoir and configured to dispose a volume ofthe liquid build material into the air-filled inner volume of theprinting space; a nebulizer configured to nebulize a coagulation agentand disperse the nebulized coagulation agent within a distance from thedisposed volume of liquid build material, wherein a first affinitybetween the coagulation agent and the solvent is higher than a secondaffinity between the coagulation agent and the polymer such that thecoagulation agent causes at least partial coagulation of the polymerfrom the disposed volume of liquid build material; and a computingdevice configured to control, based at least upon the distance from thedisposed volume of liquid build material at which the nebulizedcoagulation agent is dispersed, the first affinity between thecoagulation agent and the solvent, and the second affinity between thecoagulation agent and the polymer, movement of the nozzle and thedisposing of the volume of the liquid build material into the air-filledinner volume of the printing space.
 2. The apparatus of claim 1, furthercomprising: a solidification bath comprising a coagulation fluid, thesolidification bath configured to, in an instance in which the nebulizedcoagulation agent only partially coagulates the disposed volume ofliquid build material, receive the intermediate article and cause, viathe coagulation fluid, the intermediate article to fully solidify,thereby forming the finished article.
 3. The apparatus of claim 1,wherein the polymer comprises one of: a thermoplastic polymer, athermosetting polymer, acrylonitrile-butadiene-styrene, a polyurethane,acrylic, poly(acrylonitrile), a polyolefin, a polyvinyl chloride, anylon, a fluorocarbon, a polystyrene, a polyethylene (PE), an ultra-highmolecular weight polyethylene, a polypropylene (PP), a polybutene, apolymethylpentene, a polyisoprene, an ethylene-butene copolymer, anethylene-hexene copolymer, a polyimide (PI), a poly amide (PA), a polyamide imide (PAI), a ethylene vinylacetate (EVA), a poly(ethyleneterephthalate) (PET), a poly(vinyl acetate) (PVA), an acrylic adhesive,an ultraviolet (UV)/electron beam (EB)/infrared (IR) curable resin, apolyether ether ketone (PEEK), a polyethylene naphthalate (PEN), apolyethersulfone (PES), a polyphenylene sulfide (PPS), or apolyphenylene oxide (PPO).
 4. The apparatus of claim 1, wherein thesolvent comprises one of: dimethyl sulfoxide (DMSO), dimethylformamide(DMF), acetonitrile, ethanol, N-methylpyrrolidone, cyclodextrin, apluronic detergent, liposomes, sodium methyl sulfinylmethylide, dimethylsulfide, dimethyl sulfone, acetone, dimethylformamide,dimethylacetamide, N-methyl-2-pyrrolidone, hexamethylphosphoramide(HMPA), methanol, isopropanol, tert-butanol, acetic acid, ether,tetrahydrofuran, dichloromethane, chloroform, triethylamine, pyridine,or ethyl acetate.
 5. An apparatus for three-dimensional printing of anarticle, the apparatus comprising: a nozzle configured to receive avolume of a liquid build material and dispose at least a portion of thevolume of the liquid build material into an air-filled inner volume of aprinting space, the liquid build material comprising a polymericmaterial in a solvent; a nebulizer configured to nebulize a coagulationagent and disperse at least a portion of the nebulized coagulation agentwithin a distance of the disposed liquid build material, wherein a firstaffinity between the coagulation agent and the solvent is higher than asecond affinity between the coagulation agent and the polymeric materialsuch that the coagulation agent causes at least partial coagulation ofthe polymeric material from the disposed liquid build material; and acomputing device configured to control, based at least upon the distancefrom the disposed volume of liquid build material at which the nebulizedcoagulation agent is dispersed, the first affinity between thecoagulation agent and the solvent, and the second affinity between thecoagulation agent and the polymer, movement of the nozzle within theprinting space, the computing device being further configured to controlthe disposing of the liquid build material into the air-filled innervolume of the printing space and the dispersion of the nebulizedcoagulation agent within the printing space.
 6. The apparatus of claim5, further comprising: a reservoir configured to contain a supply of theliquid build material.
 7. The apparatus of claim 5, further comprising:a solidification bath comprising a coagulation fluid, the solidificationbath configured to, in an instance in which the nebulized coagulationagent only partially coagulates the disposed volume of liquid buildmaterial, receive the article and cause, via the coagulation fluid, thearticle to fully solidify, thereby forming a finished article.
 8. Theapparatus of claim 5, wherein, in an instance in which a volume of theliquid build material is disposed onto the substrate within theair-filled inner volume of the printing space and a volume of thenebulized coagulation agent is disposed within said distance of thedisposed volume of the liquid build material during a time followingsaid disposing of the volume of the liquid build material onto thesubstrate, the disposed volume of the liquid build material is caused toat least partially coagulate upon reaction with the volume of thenebulized coagulation agent.
 9. The apparatus of claim 5, wherein thenozzle is configured and dimensioned to move along a path within thevolume of air to dispose a volume of the liquid build material.
 10. Theapparatus of claim 9, wherein the path is determined by the computingdevice based upon an input design file comprising a design of thearticle.
 11. The apparatus of claim 9, wherein the apparatus isconfigured to communicate the liquid build material from one or morereservoirs, through the nozzle, and into the volume of air.
 12. Theapparatus of claim 1, wherein said affinity is a Hansen solubility. 13.The apparatus of claim 5, wherein the first affinity is based upon aHansen solubility between the coagulation agent and the solvent, andwherein the second affinity is based upon the Hansen solubility betweenthe coagulation agent and the polymeric material.
 14. An apparatus forthree-dimensional printing of a finished article, the apparatuscomprising: a nozzle configured to receive a volume of a liquid buildmaterial and dispose at least a portion of the volume of the liquidbuild material into an air-filled inner volume of a printing space, theliquid build material comprising a polymer dissolved in a solvent; anebulizer configured to nebulize a non-solvent coagulation agent anddisperse at least a portion of the nebulized non-solvent coagulationagent within a distance from the disposed liquid build material, whereina first affinity between the non-solvent coagulation agent and thesolvent is higher than a second affinity between the non-solventcoagulation agent and the polymer such that the non-solvent coagulationagent causes at least partial coagulation of the polymer from thedisposed liquid build material; and a computing device configured tocontrol movement of the nozzle within the printing space, control thedisposing of the liquid build material into the air-filled inner volumeof the printing space, and control the dispersion of the nebulizednon-solvent coagulation agent within the printing space, wherein thecomputing device is configured to control the dispersion of thenebulized non-solvent coagulation agent and the distance from thedisposed liquid build material based upon at least the first affinitybetween the non-solvent coagulation agent and the solvent and the secondaffinity between the non-solvent coagulation agent and the polymer. 15.The apparatus of claim 14, further comprising: a reservoir configured tocontain a supply of the liquid build material.
 16. The apparatus ofclaim 14, further comprising: a solidification bath comprising acoagulation fluid, the solidification bath configured to, in an instancein which the nebulized non-solvent coagulation agent only partiallycoagulates the disposed volume of liquid build material, receive anintermediate article and cause, via the coagulation fluid, theintermediate article to fully solidify, thereby forming the finishedarticle.
 17. The apparatus of claim 14, wherein, in an instance in whicha volume of the liquid build material is disposed onto the substratewithin the air-filled inner volume of the printing space and a volume ofthe nebulized non-solvent coagulation agent is disposed within saiddistance of the disposed volume of the liquid build material during atime following said disposing of the volume of the liquid build materialonto the substrate, the disposed volume of the liquid build material iscaused to at least partially coagulate upon a phase-inversion reactionwith the volume of the nebulized non-solvent coagulation agent.
 18. Theapparatus of claim 14, wherein the nozzle is configured and dimensionedto move along a path within the volume of air to dispose a volume of theliquid build material.
 19. The apparatus of claim 18, wherein the pathis determined by the computing device based upon an input design filecomprising a design of the finished article.
 20. The apparatus of claim18, wherein the apparatus is configured to communicate the liquid buildmaterial from one or more reservoirs, through the nozzle, and into thevolume of air.
 21. The apparatus of claim 14, wherein the first affinityis based upon a Hansen solubility between the non-solvent coagulationagent and the solvent, and wherein the second affinity is based upon theHansen solubility between the non-solvent coagulation agent and thepolymer.